The release of a new iPhone means two things. The first is obviously the new phone; but that hardware is also accompanied by a new version of iOS. Apple's mobile operating system has evolved from a relatively simple interface for using a few stock Apple apps (on 2007's debut iPhone) to an advanced system that is creeping ever closer to OS X. The annual iOS refresh is now an event in itself.

The last two iterations of iOS brought significant upgrades. 2010's iOS 4 saw multitasking, folders, and home screen wallpaper; last year's iOS 5 featured revamped notifications, iCloud, and Twitter integration. With the most obvious holes already filled, many questioned what direction Apple would take this year with iOS 6.

Let's take a look at the decisions – and execution – that Apple ultimately took with this year's update:

Maps

Apple opted to highlight its update to Maps as the marquee feature of iOS 6. That may come back to haunt Tim Cook and Co., as customers and critics have been up in arms over this initial version of Apple Maps.

The first five editions of iOS used Google Maps on the backend, with an iOS skin on the front end. However, for undisclosed reasons (hmm, the bitter rivalry between Google and Apple, perhaps?), the contract wasn't renewed and Apple created its own backend to Maps.

The sexiest new feature is called Flyover. It's an attractive bird's-eye view that lets you pan around select cities to see 3D versions of buildings, landscapes, and landmarks. Think Google Earth in a pop-up book.

Flyover is great eye candy, but doesn't necessarily serve a practical purpose. That base, however, is covered by the new turn-by-turn navigation. Android's Google Maps Navigation has been a feather in its cap for several years; now iOS has its own answer. As a nice perk, Apple's navigation is integrated with Siri ("take me to the zoo" will now provide voiced navigation, rather than a silent list of directions). It also uses live traffic data to optimize your routes.

Apple's Maps is a great start for a company that has never released mapping software … but customers have come to expect more from Apple. Steve Jobs' perfectionism is legendary, firmly ingrained in the company's DNA. So to see "updated" software that is, in many ways, a step (or three) back from the previous version raises an alarm.

Complaints about Maps have ranged from misplaced landmarks to missing towns and melted bridges. To make matters worse, mass transit directions are kaput, with the app directing users to third-party App Store apps.

To be fair, mapping data needs to be used to improve. With data from TomTom and Waze as a start, this may be the best Apple could have done from the get-go, and it should improve in time. To other companies, this would be an understandable rocky start; but Apple isn't known for releasing half-baked software (though some Siri critics would vehemently disagree).

It will be interesting to see what Apple decides to do with the dedicated Google Maps app that 9to5Mac reports is awaiting approval from Apple (update: well-connected Jim Dalrymple from The Loop says this is false). With many dissatisfied with Apple Maps as it stands, the company might attract a fair bit of criticism if it rejects it on the grounds that Google's app “competes with existing functionality.”

Those looking to get Google Maps on their iOS 6 device can add an icon to their home screen by opening Safari, heading to maps.google.com, hitting the action button from the bottom toolbar (the one in the middle) and selecting "Add to Home Screen."

Still, if you don't rely on public transit, and you don't mind the occasional hiccup, Apple's Maps is a solid initial release with two exciting new features.

Facebook

When iOS 5 launched with Twitter integration, many scratched their heads, wondering what happened to Facebook. Having long been rumored to partner with Apple, pundits speculated about a feud between the two companies. Some even thought the Twitter partnership was a direct jab at Mark Zuckerberg and company. If there was any bad blood, though, that hatchet has apparently been buried, as iOS 6 brings the long-anticipated integration with Facebook.

This feature is essentially identical to the existing Twitter integration: easy sharing to Facebook from most apps, the ability to post to your wall from Notification Center, and easy login to apps with Facebook permissions. You can also create Facebook posts using Siri …

Siri

Speaking of Apple's intelligent assistant, Siri was also (incrementally) updated for iOS 6. "She" can now give you sports scores, show movie times, and even make restaurant reservations (via OpenTable).

Siri can also launch apps ("open Angry Birds"). Jailbreakers will point out that they've been doing this for the better part of a year. New (3rd gen) iPad owners also get a taste of Siri with iOS 6.

Passbook

Many thought Near Field Communication (NFC) was a sure bet for the iPhone 5. Apple opted to skip the budding hardware technology (for now), but still created its own payment system. The result is Passbook, another service that has plenty of room to grow.

Companies who partner with Apple will integrate their apps with the Passbook app, providing an easy way to store tickets, boarding passes, and shopping cards. You can then open the app, show a barcode, and be on your way. It achieves some of the same results that NFC would, but is easier to integrate because it uses already-deployed technology.

Passbook partners at launch (list via Gizmodo) include - among others - Fandango, Major League Baseball, Ticketmaster, Target, United Airlines, American Airlines, and Walgreens. Companies planning on releasing Passbook-friendly updates soon include Delta Airlines, Amtrak, and Starbucks.

New App Store

The App Store (as well as iTunes and iBooks) has also gotten a facelift. More apps are featured on the front page in an attractive new interface. Search results also show more information about each app, and you can install or update an app without being booted back to the home screen.

Shared Photo Streams

Photo Stream, the photo branch of iCloud, also received an update. Now you can select images from your own photo stream to instantly share with friends. They can then collaborate on the cloud-based album, and like or comment on individual photos.

FaceTime over 3G/4G

When Apple introduced FaceTime video chat in 2010, it had the infamous requirement of being on a Wi-Fi network. Now that pesky limitation has finally been lifted … sort of.

The only catch is that AT&T is using this opportunity to convert customers to its new shared data plans. The carrier is only allowing cellular FaceTime for customers who switch from their old individual plans. Fortunately for US customers, they have a choice: both Verizon and Sprint are allowing 3G/4G FaceTime without restrictions.

Safari

Though Safari remains largely the same, Apple did add iCloud-synced tabs (you'll see what pages are open on other Apple devices, including Macs), an offline Reading List, and a full-screen mode for landscape use (excluding the iPad, as this feature was likely added mainly to maximize the iPhone 5's longer 16:9 display).

Mail

Apple's Mail app also saw a few additions, including a VIP inbox, the ability to insert images and videos directly into a mail composition, and pull-to-refresh.

Phone

A handy new feature gives you a couple of options when you can't take a call. Reply with a message (custom or canned), or set a reminder to return the call. There is also a universal Do Not Disturb option that turns off system-wide notifications and calls.

Are We Happy?

iOS 6 is more evolutionary than revolutionary, but it still brings some significant upgrades. Unfortunately for Apple, the story has been largely defined by the Maps complaints.

Those who have upgraded: are the Maps issues that bad, or a bit overblown? What about the other features – do they add up to a nice improvement? Please let us know in those comments below!