Theflamecrow on WoW LJ provides us with our quarterly reminder: it's probably time to update your video card's drivers, if you haven't done it in a while.
If you're on a Mac, you don't need to worry about this (Software Update's got you covered, and the latest graphics update already helped your framerate). For PCs, Nvidia card drivers can get the latest version here, and ATI card owners can grab the latest files here. If you're not sure what kind of video card you've got installed, you can just follow along with this simple guide from the last big video card reminder, or one of the many other driver update guides available.
I should warn you: 99% of the time, updating your video card drivers will fix all kinds of problems-- it'll usually help your framerate, if it needs it, and it will often clear out problems with artifacts and other graphics glitches. But doing any system activity like updating drivers has the potential to harm your system, so always follow all instructions (like turning off all other programs and restarting the PC when asked) and, if possible, have a backup ready when you update. I've never had a system problem while updating graphics drivers, but if you're not careful, it could happen.