ThinkSecret believes that Final Cut Pro 6 will finally make its debut at NAB, which takes place April 14-19. The software was originally expected at last year's NAB which instead saw the release of the 17" MacBook Pro.
Final Cut Pro 6 has been rumored to bring 5.1 surround sound editing, 1080/24p and 1080/30p DVCPROHD support (Update: Those original specifications appear to already have made it into Final Cut Pro 5.1). ThinkSecret adds that the extra development time has afforded Apple to enhance Final Cut's realtime video editing engine with Core Animation technology.
Lastly, ThinkSecret reports that the high-end Final Cut Extreme targeting Avid users will also make its debut at NAB. Little is known about the product at this time, but it is said to be a hardware and software solution with a pricetag near $10,000.