IOS 5 Release Notes - Detailed Descriptions

Question

Hi,
Where can I find more detailed descriptions of the iOS5 Software Update?  Below is what I received when I downloaded the update, but this is very vague.  I want to know more about the iMessage.
Thank you.
iOS5 Software Update
Thisupdate contains over 200 new features, including the following:
Notifications
◦                  Swipe from the top of any screen to viewnotifications in one place with Notification Center
◦                  New notifications appear briefly at the topof the screen
◦                  View notifications from lock screen
◦                  Slide the notification app icon to the righton the lock screen to go directly to the app
iMessage
◦                  Send and receive unlimited text, photo, andvideo messages with other iOS 5 users
◦                  Track messages with delivery and readreceipts
◦                  Group messaging and secure encryption
◦                  Works over cellular network and Wi-Fi*
Newsstand
◦                  Automatically organizes magazine andnewspaper subscriptions on Home Screen
◦                  Displays the cover of the latest issue
◦                  Background downloads of new issues
Reminders for managing to do lists
◦                  Syncs with iCloud, iCal and Outlook
◦                  Location-based reminders when you leave orarrive at a location for iPhone 4S and iPhone 4
Built-in support for Twitter
◦                  Sign-in once in Settings and tweet directlyfrom Camera, Photos, Maps, Safari and YouTube
◦                  Add location to any tweet
◦                  View twitter profile pictures and usernamesin Contacts
Camera improvements for devices with cameras
◦                  Double click the home button when device isasleep to bring up a camera shortcut on iPhone 4S, iPhone 4, iPhone 3GS andiPod touch (4th generation)
◦                  Volume Up button to take a picture
◦                  Optional grid lines to line up shots
◦                  Pinch to zoom in the preview screen
◦                  Swipe to camera roll from preview screen
◦                  Tap and hold to lock focus and exposure,iPad 2 and iPod touch (4th generation) only support exposure lock
Photo improvements for devices with cameras
◦                  Crop and rotate
◦                  Red eye removal
◦                  One tap enhance
◦                  Organize photos into albums
Mail improvements
◦                  Format text using bold, italic, orunderlined fonts
◦                  Indentation control
◦                  Drag to rearrange names in address fields
◦                  Flag messages
◦                  Mass mark messages as flagged, read orunread
◦                  Customize mail alert sounds
◦                  S/MIME
Calendar improvements
◦                  Year view on iPad and new Week view foriPhone and iPod touch
◦                  Tap to create an event
◦                  View and add event attachments
Game Center improvements
◦                  Use personal photos for your Game Center account
◦                  Compare your overall achievement scores withyour friends
◦                  Find new Game Center friends with friendrecommendations and friends of friends
◦                  Discover new games with custom gamerecommendations
AirPlay Mirroring for iPad 2 and iPhone 4S
Multitasking Gestures for iPad
◦                  Use four or five fingers to pinch to theHome Screen
◦                  Swipe up to reveal the multitasking bar
◦                  Swipe left or right to switch between apps
On-device setup, activation andconfiguration with Setup Assistant
Software updates available over the airwithout tethering
iCloud support
◦                  iTunes in the Cloud
◦                  Photo Stream
◦                  Documents in the Cloud
◦                  Apps and Books automatic download andpurchase history
◦                  Backup
◦                  Contacts, Calendar, and Mail
◦                  Find My iPhone
Redesigned Music app for iPad
Hourly weather forecast
Real-time stock quotes
Wireless sync to iTunes
Keyboard improvements
◦                  Split keyboard for iPad
◦                  Improved autocorrection accuracy
◦                  Improved Chinese and Japanese input
◦                  New Emoji keyboard
◦                  Personal dictionary for autocorrection
◦                  Optionally create keyboard short cuts forfrequently used words
Accessibility improvements
◦                  Option to light LED flash on incoming callsand alerts for iPhone 4S and iPhone 4
◦                  Custom vibration patterns for incoming callson iPhone
◦                  New interface for using iOS withmobility-impairment input devices
◦                  Option to speak a selection of text
◦                  Custom element labeling for VoiceOver
Exchange ActiveSync improvements
◦                  Wirelessly sync tasks
◦                  Mark messages as flagged, read or unread
◦                  Improved offline support
◦                  Save a new contact from a GAL service
More than 1,500 new developer APIs
Bug fixes
Productscompatible with this software update:
iPhone 4S
iPhone 4
iPhone 3GS
iPad 2
iPad
iPod touch (4th generation)
iPod touch (3rd generation)
*Normal carrier data rates may apply. Messages will be sent as SMS when iMessageis unavailable, carrier messaging fees apply.
Forinformation on the security content of this update, please visit this website:
            http://support.apple.com/kb/HT1222"

Answer 1

You will need to look in Apple's developer documentation
http://developer.apple.com/
or perhaps there is or will be an in depth review at Ars Technica
http://arstechnica.com/apple/