This is from the late breaking news bit on apples website.
QUOTE
Shake and Final Cut Pro display and process the gamma of QuickTime movies and RGB
image files differently.
Shake makes no automatic changes to the gamma of QuickTime or RGB Image files and
sequences. It is up to users to make sure that their monitor is properly calibrated for
their production environment, and that the ViewerLookup parameters are set to the
values required for images to display properly in the Shake Viewer. In particular, the
default viewerGamma value is 1, which leaves the gamma of images displayed in the
Viewer unchanged.
Final Cut Pro, on the other hand, makes some assumptions about the gamma of
QuickTime and RGB image files that are imported into a project. The gamma of
imported QuickTime and RGB image files is treated differently in sequences set to
render in 8- or 10-bit YUV.
Note: While it is possible to recalibrate Apple displays via the Display Calibrator
Assistant in the Displays pane of System Preferences, users are advised to leave the
gamma of their monitors to the 1.8 Standard Gamma setting when working in
Final Cut Pro. ColorSync settings are not used by either Shake or Final Cut Pro for
automatic color calibration or compensation of any kind.
QuickTime Movies
Issue: When importing a QuickTime movie created with Shake into Final Cut Pro,
users may notice a difference in the displayed gamma of the image. This is because
Final Cut Pro automatically lowers the gamma of sequences playing in the Canvas on
your computer