Back to cell processors.
1) Multiprocessor in the same wrapping... But its just a multiprocessor.... Will it be a problem?
But... Now consoles come with much better development kits. The trouble with the Saturn was nobody wanted to program for it. To hard... to confusing... to hard to optimize on the hardware to utilize both processors.
But with APIs that are already optimized to use mulitiple processors. Hopefully this will help.
Also, it sounds like the processors can be completely setup differently. Heck, you can have 1 or 10 running OSX and 2-5 running WindowsXP and 6-10 running a gaming system. If its as configuratble as they say, I can see it very nice for splitting applications... Like adding TIVO support while your playing video games... That would be cool.
2) Its a PS3... They will have developers for it no matter what. Heck, Sony could come out with a PS3 powered by a pentium3 with CGA graphics and they would sell a ton. They get one sucky console before people second guess their hardware

3) The cell (IMHO) has the ability to be the next powerpc. REALLY cool on paper... but will it take over the x86 chips? Only if intel / amd can't come close on the power it has for a LONG time. They will have a struggle. But if when they create a desktop version... if they can emulate a x86 well... I could see them taking over in a few years..