I see it as a boon! It means and 'ASM' level optimizations that are done could be reused on both platforms. Very cool.
Yes. Except nobody does that anymore, because it's a waste of time with processors as fast as they are today, and compilers being as good as they are. I think Pentium are very good processors, It can be very interesting...
Compared to what? I think the impending transition is more of a reason to buy a PowerPC Mac now if you need one.
I see it as a reason to finally buy a cheap PC. I can't think of a single application that you can get, which is exclusive to MacOSX, and WindowsXP isn't much worse than OSX (from a users perspective) - even if you do have to reinstall it more often.