Gaming on the Mac would still be possible through Boot Camp. I think it's just the games that are made to run natively on the Macs that will get the axe. My buddies have been playing Counter-Strike on their Macbooks so I'm sure that Mac gaming would still be alive, just not natively.
running emulation will just kill any performance of the game i reckon plus most macs are low spec compared to gaming pcs these days, unless you have a ridiculously powerful and expensive mac