New features:

Logic Pro 9:
Flex Time (Elastic Audio equivalent)
Audio Quantize
Bounce in Place
Selective Track Import (choose media, plug-ins, i/o, sends, etc...)
Drum Tracks Editing
Speed Fades (Turntable-style start and stop)
Auto-conform tempo when importing audio
Varispeed
Drum Replacer
Editing within Take Folders
Possibility to assign a channel strip to multiple groups
Channel Strips now have a mono output option
Track Notes in the Mixer
Control Surface bars in the Mixer
Convert Audio Region to Sampler Instrument
Freeze tracks: source only (before plug-ins) or pre-fader (after plug-ins)
Guitar Chord grids with hammer-on, pull-off, bends notation
Amp Designer
Pedalboard
Live Loop Recorder
Space Designer Warped Effects
All 6 Jam Packs (including newer "Voices" Jam Pack)

MainStage 2
MIDI Out
ReWire support
Loopback & Playback plug-ins
Live Audio Recording
Amp Designer
Pedalboard
Multi-mapping of controls (one knob = several parameters)

Soundtrack Pro 3
Consolidated Multitrack Timeline & File Editor
Support of Euphonix control surfaces