This is the official list of improvements:
iOS 4.2 Software Update for iPad
This update contains over 100 new features for iPad including support for multitasking, folders, unified mail inbox, Game Center, AirPrint, AirPlay and many system improvements. It is highly recommended for all iPad users.
iOS 4.2 for iPad includes the following:
• Multitasking support for third-party apps
- Multitasking user interface to quickly move between
apps, adjust screen brightness, control playback,
lock screen rotation and manage print jobs
- Support for audio apps to play in the background
- VoIP apps can receive and maintain calls in the
background or when the device is asleep
- Apps can monitor location and take action while
running in the background
- Alerts and messages can be pushed to apps using
push and local notifications
- Apps can complete tasks in the background
• Folders to better organise and access apps
• Mail improvements
- Unified inbox to view emails from all accounts in one
place
- Fast inbox switching to quickly switch between
different email accounts
- Threaded messages to view multiple emails from the
same conversation
- Import .ics files into Calendar
- Open attachments with compatible third-party apps
- File or delete search results
- Option to select size of photo attachments
- Messages in the Outbox can be edited or deleted
• Game Center
- Send and receive friend requests
- Invite friends to multi-player games over the Internet
- Play multi-player games by auto-matching with other
players
- View Leaderboards and Achievements
- Discover new games from friends
• AirPrint
- Print mail, photos, web pages and more directly to
AirPrint-compatible printers on a local wireless
network
• AirPlay
- Wirelessly stream videos, music and photos to
Apple TV
- Wirelessly stream music to AirPlay-enabled speakers
or receivers, including AirPort Express
• Find text on web pages in Safari
• Use Spotlight to search the web and Wikipedia
• Suggestions and recent searches appear during a web
search
• Support for TV programme rentals using iTunes (US only)
• Create and edit iTunes playlists on your device
• Support for iTunes gifting of apps
• Send and accept calendar invitations wirelessly with
supported CalDAV servers
• Support for MobileMe calendar sharing
• Enhanced location privacy
- A Location Services icon appears in the status bar to
indicate when Location Services are being used
- Location Services can be enabled and disabled per
app
- Indication of apps that have requested your location
within the last 24 hours
• Additional Parental Controls
- Prevent adding friends in Game Center and deletion
of apps
- Restrict changes to Accounts and Location Services
settings
• New languages, dictionaries and keyboards
• New fonts available in Notes
• Wirelessly sync notes using IMAP-based mail accounts
• Automatic spellcheck
• Silence background sounds using the Silent switch on
the side of iPad
• Improved support for Bluetooth AVRCP
• Persistent Wi-Fi connection to receive push notifications
• Support for Bluetooth braille displays and international
braille tables, control VoiceOver using an external
keyboard, and other accessibility enhancements
• Wireless delivery of carrier settings updates for
iPad with Wi-Fi + 3G
• Improved enterprise support
- Support for third-party Mobile Device Management
solutions
- Enables wireless distribution of enterprise applications
- Exchange Server 2010 compatibility
- Support for multiple Exchange ActiveSync accounts
- Support for Juniper Junos Pulse and Cisco
AnyConnect SSL VPN apps (available from the App
Store)
• More than 1,500 new developer APIs
• Bug fixes
Products compatible with this software update:
• iPad
• iPad with Wi-Fi + 3G