It just might. I've thought for a long time Apple should switch to Intel and make OSX available for standard "PC's", and if they can configure a virtual machine or 'live cd' that boots on Dell or other cheap PC's they will will make some serious noise in the desktop O/S market.
I agree, a solid Unix like OS with lots of apps would gain market share.
I've put Unix on a 486 years ago, very fast, the hard ware is not the problem. X-Windows is not the problem. Don't know why Linux is slow, but I don't think the Unix kernal or X is why.