Ohh, shiny screen.
Too bad that A, that large a resolution probably won't be supported by a 4850 in games, and B, it's a Macintosh. Macs don't deal with games too well, in case Apple hasn't noticed yet :| Very few commercial games support Windows AND Mac, and bootlegging/emulating more often than not is a buggy and unreliable process, even if you know what you're doing.
tl;dr: IRONIC FAIL.
(Insert here a comment about how you could get a PC at half the price with the same power etc)
A 27" screen cannot be adequately powered by a 4850 in 99% of games, as they suggested you would play.
However, 99% of games don't run natively on Macs, so why are they pushing that?