Here's how it is.
This is genius and Bill Gates should be worried. Mac OS has the ability to be the Windows killer that Linux can't be yet(it's always too bleeding edge), Linux is too involved for those who are just looking to get something done(I suppose the Morts), also Linux has to keep itself in a legal safe house(see how quick people moan when they can't play their DVDs or play an mp3 file out of the box).
I've seen some of the dumbest people out paying £300+ for a iPod only to find out they need a computer?!(No it's true) When Mac OS can easily be installed on an Intel machine and provide all the multimedia and productivity that Windows does then Microsoft has a problem. Also Apple doesn't doesn't have to be backward compatible with almost 20 years worth of (some bad) software like Microsoft does (something often overlooked). 'My armymen game that came bundled with Win95 doesn't work no more' - Irate Customer.
So I see this as an aggressive move into the desktop market, the kingdom where Microsoft rules.
Obviously it's going to upset the Apple faithful, nobody likes it when their favourite band that only a few 'cool' people like goes big time and everyone's listening to them.