I installed Windows 7 64-bit on a 13" MBP Mid-2009 (Core 2 Duo 2.2 GHz, 2 GB RAM, 9400M) and TOR is barely playable. In areas like the Jedi Temple it goes under the 10 fps mark but in open areas it's pretty stable between 25-30 fps. It's more fun playing with a better machine though.