I just picked up the newest 13 inch macbook pro base model last night, and while I haven't played UT on it for a large number of hours, the laptop with stock UT at 1280x800 runs between 40 and 100 FPS on wifi, FallinAngels with 20 people on it from San Diego (~100ping), about the same as my last 15in macbook pro with an ATI Radeon X1600 256mb. Quite playable. I'll hook it up to a 1080p monitor when I get my hands on one and let you know what frames I'm getting then.
I normally play on a GTX 260 core 216 paired with a phenom II x4 955 but now I can play on the road. Huzzah.
EDIT:
/timedemo 1
/demo tutorial
results in ~270fps
This post has been edited by Taenon: 22 April 2010 - 08:24 AM