Please post what you have, be it a statistical 3dmark06 test, average of your FPS in a certain game, video stress test, whatever. Let's get out there what these things can do so that those who are unsure (myself) can decide what system is for them.
Steam for Mac should be here ASAP and then we could really see, however it is not available yet ;/ Thanks guys.
Edit: here is a YouTube Modern Warfare 2 on a 15" low end i5. (runs pretty well considering it's the low end)
http://www.youtube.com/watch?v=_ZOOuLDTcas
Bad Company 2 Here
http://www.youtube.com/watch?v=4-Gqh2uu9ik
Call of Duty World At War
http://www.youtube.com/watch?v=tM6WPZQI2CQ
Crysis (Kinda)
http://www.youtube.com/watch?v=U_TtaAUgfok
Punk ass kid reviews the 15" 2.53 and plays some Crysis Wars (skip to 8:40)
http://www.youtube.com/watch?v=ao84oWkrvwU
StarCraft II pic
(average 40 FPS on low end i5 {All High, 1440x900)
Bad Company 2
1280x800
4xAF
2XAA
Medium Settings
(Again low end i5)
30 - 60 FPS (but mainly 30's)
Steam for Mac should be here ASAP and then we could really see, however it is not available yet ;/ Thanks guys.

Edit: here is a YouTube Modern Warfare 2 on a 15" low end i5. (runs pretty well considering it's the low end)
http://www.youtube.com/watch?v=_ZOOuLDTcas
Bad Company 2 Here
http://www.youtube.com/watch?v=4-Gqh2uu9ik
Call of Duty World At War
http://www.youtube.com/watch?v=tM6WPZQI2CQ
Crysis (Kinda)
http://www.youtube.com/watch?v=U_TtaAUgfok
Punk ass kid reviews the 15" 2.53 and plays some Crysis Wars (skip to 8:40)
http://www.youtube.com/watch?v=ao84oWkrvwU
StarCraft II pic
(average 40 FPS on low end i5 {All High, 1440x900)

Bad Company 2
1280x800
4xAF
2XAA
Medium Settings
(Again low end i5)
30 - 60 FPS (but mainly 30's)
