Based on murmurings and mooings on the pro sites, I reckon Apple will lose some customers to Avid, if they had originally come from Avid some time in the last 10 years. They're talking about going back to Avid, not to Avid.
I also reckon every kid who has used iMovie in the last few years will start using FCP X in about July. This is the next generation of video editors, and they will far outnumber Avid users. They will be making movies for web distribution. They will be flooding the film schools. They will also have the mad skillz (look at me, sounding like a teenager) to turn things over really quickly, something which is appreciated in today's editing environment.
Apple has built FCP X for people who have never used film and probably never will so the metaphor needed to go. Bye-bye bins, hello "smart folders". And a big hello to the do-deca-core, 8TB, 32GB Mac Pro everyone can now justify purchasing.
i second this as well.
as a side note, most of the editors i know don't think twice about switching back and forth btn fcp and avid based on the project /client requirements regardless of their particular preference.
ultimately the result of apples move will only come to light after the software is released and peeps get their hand on it. everything now is just looking at screenshots.