My 2008 MacBook Pro runs it on low settings. Game runs like shit regardless of what machine you play it on.
bummer
I got it running on my gf's '07 MBP (256MB 8600MGT), and with shadows off/everything low, we were able to get a pretty steady 30-40 fps (outside of the fleet). Warzones/normal questing were perfectly fine, even Illum was ok to some extent.
Was actually pretty surprised (granted, not as good performance as WoW, but different beasts); only real downside was performance degraded pretty fast (2-3hrs it got VERY hot and performance was cut in half/choppy). Restart fixed it, but annoying.
tl;dr: it's do-able, but they still have a LONG way to go inorder to optimize the game for older systems (newer too , to some extent)