New Features:
- Locations can now be specified as addresses, previously latitude/longitude coordinates must be used
- Paths can be specified as encoded polylines
- Paths can be filled and rendered as polygons
- Colors can now be specified as any 24-bit or 32-bit color

For version 1 users (including me), here is the upgrade guide.
Other relevant resources:
Developer's guide | Official BLOG | Google Static Maps 2 Wizard