Some of the amazing new features for developers:
- Unified UI framework for phones, tablets
- Social API
- Calendar API
- Visual voicemail API
- Android Beam
- Low-level streaming multimedia
- Media effects for transforming images and video
- New media codecs and containers (support for Matroska!!)
- Wi-Fi Direct
- OpenGL ES texture views
- Hardware-accelerated 2D drawing
- VPN client API
And a lot more! Checkout the full change log here
Developers, don't forget to read the hightlights and the differences report.
oh, and watch the cool promo video