Naw. Would suck ass.
Keep OSX on Apple products. If they allowed OSX to run on any joeschmoe computer they would be shooting themselves in the foot. OSX is one of the main reasons (if not the main reasion) that people buy Mac Hardware. Yeah you would still get sales of their products but the numbers would dwindle as people could just pay 140 quid and install it on their run of the mill Dell.
Also, if Apple were to support other computers, then they have to start making it compatible with every hardware setup possible. With them just support their own hardware its much easier for them to keep OSX running tip-top.
I am really happy that Apple are building their reputations and market share and all that - but I really would hate to see them become so big that virus coders/spyware making ********* think OOOOO lets attack the new big boy - and before you know it we have to isntall A/V on our Macs. Now that would suck arse.