Have you actually chained like 10 mac minis and used them to render something? It should most certainly beat any Mac Pro out there, while costing around the same. I know it would only work for the Compressor distributed rendering, but still, isn't that the thing which takes the most time?
by using the word 'should'...most certainly beat, I have to ask - have you personally daisy chained 10 mac minis?
Sure the costs of the 10 minis might be the same as 1 MP, but that's a whole pile of extra power cables etc...to power them up and chain them. I have a G4, G5, 2009 MP, 2010 MP and a 2006 MP in my office and there's enough cables from those machines to drive me nuts. I couldn't imagine anymore!

Let's not even get into footbrints around the work area either lol
Sorry...I'll take 1 machine to do the work of 10 anyday.
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Regarding the world of pros leaving FC and Apple - I don't blame them. For me, FCX works, as an individual and someone not cutting feature films or commercials. Basic edits is what I need, plus occasional extras and FCX/Compressor work for me.
BUT, these are tough economic times and if a tool or set of tools will allow one to do their job more efficiently than the next person and prepare them for new technologies, thus enabling them to keep getting hired, I say go for it. I fear that editing has become like photography and journalism where reduced software and hardware costs have created 'sudden professionals' who undercut the real pros thus diluting the markets.
You can love or hate FCX, but even if you love it, you can not (with an educated mind), disagree with the fact that the future of the Final Cut line was not communicated properly at all by Apple.
I can't wait for the updates myself. I'm still hoping they have a better solution (ie. an updated DVD Studio Pro app) for blu rays, but then again, the new AppleTV output capabilities help erase a chunk of that need.