For those into very serious blue-screen and compositing effects, Apple has announced Shake 3, and upgrade to the compositing package they purchased in February of 2002.
The package is pricey ($3900 on the Mac, and $9900 under Linux and IRIX), but it is acknowledged to be the best product in its group, and a must for serious movie making.
Of further interest is the licensing for network render units. These allow you to off-load the work from the GUI machine to machines that do nothing but the hard work necessary to put the film frames together. On the Macintosh, you get them for free. Under IRIX or Linux, you will be paying on a per-seat basis for floating licenses.
The design of the pricing is to make it cheaper to buy Macs than it is to upgrade your software license. Although Apple doesn't disclose if it is working, they certainly made a number of acquisitions last year aimed at that goal.