This Wednesday, at their annual special music event, Apple will most likely introduce the final version of iOS 4.1 for iPhone and iPod touch (though probably not for iPad). Apple released the first beta for iOS 4.1 on July 14 and stuck to their every-two-weeks cycle for beta 2 on July 27 and beta 3 on August 3.

What we've seen so far includes a new, font-crazy version of Game Center, which was also included in the iOS 4 betas but removed for the general release, and FaceTime connections over email, which will be required for non-phone devices like iPod touch 4.

It will also likely contain bug fixes for the proximity sensor, and hopefully performance fixes for iPhone 3G.

Those features are certainly impressive, those fixes certainly much needed. But is that all we'll get? There's no way to know what Apple will do in the future, but we can look at what they've done with past iOS x.1 releases for clues...

Update 2: iOS 5.1 has now been released.

Update 1: iOS 4.1 has now

iOS 3.1 (iPhone 3.1)

iOS 3.1, originally referred to as iPhone 3.1, was released on September 9, 2009 following Apple's It's only rock and roll but we like it special music event. It fixed issues with iPhone 3G Wi-Fi and icon display. It also added:

  • Triple click Home for accessibility options
  • Voice control over Bluetooth
  • Remote passcode lock with Find my iPhone
  • Save MMS to camera roll
  • Event location in popup alert
  • Non-destructive video clip trimming
  • Tethered data usage stats
  • Fraud warnings toggle for Safari
  • iTunes account credit display
  • Top Grossing in App Store
  • Genius for apps
  • Genius mixes
  • Copy and paste in Phone and Contacts

iOS 2.1 (iPhone 2.1)

iOS 2.1, originally referred to as iPhone 2.1, was introduced on September 9, 2008 at Apple's Let's rock special music event and released on September 12, 2008. It fixed problems with call drops, battery life, backup times, email reliability, 3rd party app installation speeds, SMS performance, contact loading and search, "improved accuracy" of 3G bars (which have since been "corrected" again in iOS 4.0.1). Features included:

  • Screen shot added camera shutter sound
  • Load earlier SMS messages
  • SMS alert repeat
  • Disable Camera in Settings Restrictions
  • Option to wipe data after 10 failed passcode attempts
  • Genius playlist creation
  • Tap icon to pause/resume app install
  • App icons remain in place following on-device update

Note: Unlike iOS 3, where iOS 3.2 was exclusive to iPad, there was an iOS 2.2 (iPhone 2.2) update for iPhone and iPod touch. iPhone 2.2 added Google Street View, Transit and Walking directions, the ability to turn off auto-correct, audio and video podcasts in the iTunes Store app, App Store "rate app on delete" (since removed in iOS 4), the return of Update All for apps, and a rejiggered Safari search bar.

iOS 1.1 (iPhone 1.1)

iOS 1.1 (iPhone 1.1) was originally shown off on the first generation iPod touch on September 14, 2007 during Apple's The beat goes on special music event, but was released as iOS 1.1.1 (iPhone 1.1.1, or September '07 update) for iPhone on September 27. Added were:

  • iTunes Wi-Fi Music Store app
  • Louder speaker volume
  • Double click home to launch favorites or iPod controls
  • Double tap space bar for a period (.)
  • Landscape support for Mail attachments
  • Re-ordering for Stocks and Weather items
  • Apple Bluetooth headset (RIP) battery status
  • Disable roaming data
  • Additional passcode lock time settings
  • Adjustable alert volumes

There was no iOS 1.2 (iPhone 1.2) update, but there was a significant iOS 1.1.3 (iPhone 1.1.3 or January '08) update shown off at Macworld on January 15, 2008 that added Mail, Maps, Stocks, Weather, and Notes to iPod touch (for a price), gave Google Maps the "locate me" function, introduced "jiggly mode" to re-arrange icons, added iTunes gift card redemption on-device, gave lyrics to music, let you add Web Clips to the home screen, enabled multi-person SMS, included Gmail as a default set up type, made the keyboard multitouch, and put chapters, language, etc. into movies.

So what does this mean for iOS 4.1?

Smaller version updates mean smaller feature additions. If you're holding out hope for a brand new notification system you'll probably have to wait for next March and the iOS 5 sneak preview event. If Game Center, and FaceTime moving beyond the iPhone, interest you, then you'll probably have lots to be happy about. It's always possible we'll get "One more thing..." but looking back over previous iOS x.1 (iPhone x.1) updates, I'm not holding my breath. Too much.