Yes, there are still Mac-specific video cards, for whatever reason. AMD's cashing in on the need; pushing the X1900 out to those big film gurus with a need for high-end graphics. Of course, the argument can certainly be made that those who own G5 machines would be using workstastion cards...

"At an estimated street price of US$349, the ATI Radeon X1900 G5 Mac is a state-of-the art design with 36 pixel shader processors, 256 MB of video RAM and delivers over 37 gigabytes per second of memory bandwidth. It features two DVI ports that are capable of supporting two 30-inch Apple Cinema HD Displays."