iOS6 feature list:
Small details
1. Adaptive status bar [Screenshot, Screenshot2]
2. Metallic Sliders in iPod.app change if you tilt left or right [Screenshot Left, Screenshot Right]
3. Darker Camera UI
4. âNewâ Banner when you ahve installed a new app [Screenshot]
5. Full version history(With release notes) for apps [Screenshot]
6. Shut down spinner logo is now retina
Maps
1. New maps
2. Flyover 3D mode
3. Traffic
4. Turn by turn navigation
5. Siri integration
6. Landscape mode [Screenshot] *NEW*
iPod
1. New controls while playing a podcast [Screenshot]
2. Redesigned skin [Screenshot]
Safari
1. iCloud Tabs
2. Full-Screen Landscape
3. Offline Reading List(full webpages)
4. File Uploads
5. Crossfade CSS Function
6. Remote web inspector
7. Smart App Banners [Screenshot]
8. CSS Filters
9. Web Audio API
10. Redesigned Share Button [Screenshot]
11. Hold on arrows and history will be revealed(new for the iPhone)
12. App in Safari search results
13. Faster Safari JavaScript
14. Re-sampling JPEGs better (2MP -> 5MP on Retina devices)
Siri
1. Siri for iPad
2. Launch an app
3. Ask Siri for movies,sports,restaurants
4. Siri integration inside new maps
5. Tweet
6. New languages: Canadian English/French, Spain/Mexico Spanish, Italian, Swiss French/German/Italian, Korean, Chinese for Taiwan/HK/PRC
7. Eyes Free integration [More info]
8. Ask for your location
Stores
1. Redesigned Stores [Screenshot1,Screenshot2]
2. Like an appâs Facebook Page [Screenshot]
3. Download an app without exiting the AppStore
4. Updating an app wonât ask for AppStore password
5. Already installed apps are now show an âOpenâ button
Mail
1. Pull to reload [Screenshot] [Video]
2. VIP Lists
3. Double tap to insert photos and videos
4. Per account signatures
5. Flagged mailbox
Phone
1. Reply with iMessage [Screenshot1, Screenshot2]
2. Remind me later [Screenshot]
3. Do not disturb mode [Screenshot]
iPad
1. Siri for iPad
2. Redesigned Stores
3. World Clock [Screenshot]
4. New Stopwatch (different from iPhone) [Screenshot]
5. New Timer (different from iPhone) [Screenshot]
6. New Alarm Clock (different from iPhone) [Screenshot]
7. Usage and standby hours in settings app [Screenshot]
Other
Facebook intergration
Tweet from notification bar
Post to Facebook from notification bar [Screenshot]
Share Photo Stream
Facetime over 3G
Passbook
Acessibility
New Features for China
Wake up to a song [Screenshot]
Autocorrection for every keyboard
Bluetooth MAP support
Improved keyboard
IPv6 support for Wi-Fi and LTE
Location based reminders for iPad
Manual location entry for reminders
Manual reorder of reminders
Manual reorder of reminders
Word highlights for speak selection
Game Center friends from Facebook
Global network proxy for HTTP
HDR improvements
Kernel ASLR
Personal dictionary in iCloud Search all fields in Contacts
VoiceOver improvements
iTunes Music Preview plays over anything [Screenshot]
More and new emojis [Screenshots]
New White dialing screen
Menu bar is no longer glossy
Goverment alerts(emergency alerts,AMBER alerts) [Screenshot]
New dialer layout [Screenshot]
SpotLight shows the name of the folder an application is in
Source:
https://docs.google.com/document/d/1LF0PFWOT5tjj7rmGz5G4NVn6zMAbMxximJr5E1lwmoQ/mobilebasic?pli=1