I didn't know if you can change it.
I use a screen res of 1280x1024 on 19" displays and the font size (visual guess) is about 10/12 point, which is about the same (visually) as the default text size for this forum. IE7 gives the zoom option but I never need to use that for text as I don't have any bad habits.
Being able to adjust would be nice as I know one or two people who insist on running the highest possible (Windows) sceen resolution on small monitors and then moaning that they can't see anything.
Come to think of it, this minor criticism applies to a couple of other editor/compilers I use. I just sit closer to the screen
(just kidding).