I think the best replacement for FCP-X is FCP 7. I'll be staying put - making money on my current machine for the foreseeable future. I haven't seen any features in X that are so compelling as to switch to anything else right now.
I was a Media Composer editor for many years and like the industry standard of AVID. I've played with Premiere 5.5 and think the metadata handling is pretty cool (especially the sound to text transcription)
If I had a crystal ball, I would say that Production Premium is going to take the place of Final Cut Studio as the go to application suite for a well-rounded solution. Look at what Adobe did to Quark when Quark pissed off its customers by not delivering an OS-X native application in an acceptable amount of time.
Andrew Wilson
WestView Digital Video & Design
http://www.westviewdigital.com