Dunno yet, installing off the disc as I write. When I first played the open beta I had serious fps issues - the first few seconds of the game was ok, after that everything was in slow-motion - literaly. Some tweaking about later I had some luck with adjusting the native screen resolution (from within the os) to 800x600 before starting the game with the same screen resolution. Still a bit of lag in multiplayer at King Leoric though.
I'm going to try this again if I encounter probs, also some of the other tweaks (no shadow and no trilinear filtering). Note that I played the beta with OS 10.7.3, 15GB HD free and 4GB RAM, since then I have upgraded to 10.7.4, 8GB RAM and cleared up 40GB of HD space.
MBP 13" medio 2010, 2.4 MHz Intel Core 2 Duo, 320M
---edit: no luck. Guess boot camp is next... :(
the trilinear thing mentioned here http://us.battle.net/d3/en/forum/topic/5235393584
does make a difference though. Went from 3-9 fps to 9 to 13-15, sometimes even 30, but still not good enough.