Apple’s iPhone OS 4.0 announcement is now available to download from iTunes here. If you don’t want to download it, you can watch in online here as well. Also, check out the iPhone OS 4.0 announcement round up that PocketFullOfApps posted too. Apple also has released over 1500 new APIs for developers to use, some of which are:

• Date data detectors
• Calendar access
• Address data detectors
• Automated testing
• Block based animation
• iPod remote control accessories
• In-app SMS
• Regular expression matching
• Performance profiling tools
• Accelerate (2000 API’s for hardware accelerated math functions)
• Date formatters
• Spell check
• Photo library access
• Image I/O
• Embed PDF metadata
• Draggable map annotations
• Half-curl page transition
• Quick look
• Power analysis tools
• Full map overlays
• Call event notification
• Full access to still and video camera data
• ICC profiles

The announcement video is just shy of 1 hour and weighs in at 170 MB.