Creating a RAMDRIVE works, especially for people with not as great hardware, but a lot of RAM.
http://www.swtor.com/community/showthread.php?t=154568
I posted my batch file on page 15.
A RAMDRIVE essentially creates a high speed SSD, which solves the caching issue that causes most of the lag in-game.
A bit technical for many, but if you can get it working the difference is night and day...
With a RAMDRIVE set up I was able to play swtor on my netbook (although only 15-20 fps )