Apple have released details of the new firmware for the iPhone.
In-App Purchasing: Allows developers to sell additional content from within applications. Highlighted uses include magazine subscriptions, eBooks, additional levels and items for games.
Peer-to-Peer Connectivity: Find other devices running the app via Bonjour over Wi-Fi of Bluetooth. Good for gaming, but also other applications for sharing data.
Third-Party Accessory Apps: Allowing accessory manufacturers to create applications to interface with their hardware accessories.
Push Notification: Rather than using background processes that hamper battery life, utilize third-party server to push badge, text, and audio alerts from applications.
Turn by Turn: Apple will allow developers to use CoreLocation for turn-by-turn GPS directions.
Cut, Copy and Paste: Available across all apps. Shake to undo or redo.
Landscape keyboard: Available in all key applications, including Mail.
MMS: Picture messaging now available.
Voice Memos: Record notes, lectures, interviews, etc.
Spotlight Search: Available across all applications. Systemwide search available from main home screen by flicking to the left.
A2DP Bluetooth: Support for stereo bluetooth headsets.
In the Q&A Apple did say if the carriers supported it they would support tethering as a modem.