I've been using Final Cut Pro since v.1.0 (got the t-shirt to prove it, yeah I'm a loser) and I'm all for an FCP rewrite. The weakest points of the app have been the same for as long as I can remember and I'm surprised it runs as well as it does today. Don't get me started on some of the things that drive me crazy, but overall it's such an incredible tool.
Apple is a hardware seller and I'm thinking a rewired FCP will actually renew interest in the Mac Pro line. Imagine how many 8-core machines Apple could sell if one of its flagship applications could actually make use of that hardware.
I really hope they re-work the Suite as a whole. Roundtripping to Color and back is killing me when finishing complicated projects on a deadline. If only they could integrate these applications into a single unit somehow. I also find it encouraging that Randy is on the team. Afterall, unless I'm mistaken, isn't he the one that gave birth to FCP's UI in the first place? More power to you, Apple. I'm ready for a change and can't wait to see what's coming next.