I can’t see any established Post Production business adopting FCPX. If Apple keep developing FCPX it will be a major threat to many post houses business model and therefore it is in there interests not to work with it. How much do you charge for a FCPX Dry Hire when the producer sitting next to you has it on their latest MacBook Pro? Or if someone develops a colour accurate laptop screen?
This is part of the reason Post Production services has been named (along with print newspapers) as an industry in terminal decline (https://tinyurl.com/6weqwll). FCPX is not complicated to use (just different) and anyone would be producer coming out of college, who is interested in the industry, will be able to do pretty advanced edits on it. I think people will always pay for talent (I hope anyway) but the industry is changing fast, the technical side of making content is becoming easier and cheaper and importantly broadcasts days are numbered….
What I’m trying to say is the success or failure of FCPX won’t be measured by how many Post Production houses use it (they won’t) but how many in-house post-services, producers and small 1 or 2 man bouquets house use it for part of there work.