Final Cut X is now available from the Mac App Store for $299 along with Motion 5 and Compressor 4 for $49.99 each.

Apple unveiled the completely rebuilt FCX at this year's National Association of Broadcaster's Conference, touting the programs new 64-bit architecture, something competing programs have had for over a year. The programs sports a completely revamped magnetic timeline, and absorbs the functionality of a number of programs that used to make up the Final Cut Studio Suite.

However, with the new software taking advantage of the 64-bit platform and GPU acceleration, some older Macs wont be compatible. Mac Pro users with older ATI graphics cards seem to be the culprit. However, Apple's Mac Store wont allow users with incompatible hardware to download the program. Hooray for OS integrated app stores.

Still, there seems to be some early backlash from the pro community. 9 to 5 Mac had a pro reader write in explaining these frustrations:

The new final cut pro x is being received very badly by pro editors. There is not support for many of the key features required in pro editing. Namely: No support for previous FCP project files. No support for output for tape (used in TV companies) no support for EDL and no support for XML. This is unequivocally not a a Professional program. Unless Apple release some updates addressing these key issues which mark the divide between consumer and pro, the pro community will very quickly leave apple behind.
In-depth reviews are still a long ways out. I myself will be getting my hands on the software soon, and will be giving my thoughts on the changes to FCX.
Source- modmyi