Just in case you haven’t noticed, I’ve changed the font and its size for main posts. I don’t know if it was my eyesight going, but it was becoming dificult for me to read it.
You can always use the Ctrl and Mouse Wheel (press Ctrl on the keyboard and spin the mouse wheel up and down to change the size of the text on both IE and Firefox).
Let me know via email if the font is too big on your screens. I run mine at 1600×1200, sometimes even bigger. As this is not one of my commercial sites I don’t really have time to do the testing that I would normally do on those sites.