FCS2 includes a bunch of major upgrades to Apple's video production tools, including: Final Cut Pro 6, Motion 3, Soundtrack Pro 2, Compressor 3, DVD Studio Pro 4, and a new color grading application called Color.
Also brand-new is Final Cut Server, the fruit of Apple's recent acquisition of asset management company Proximity and their ArtBox software.
In case you missed it, Apple has posted a really nice NAB gallery and Engadget has the full blow-by-blow keynote coverage with pictures.