I don't know what the hell happened with the site font but I'm guessing it's thanks to the recent site update we performed and IPS chose to make some changes to default font styles we were using with the old version.

Yea, I'd rather have the old font styles back too. The Journal font for entry headings is especially horrible - it looks like an alpha channel has been added to the font that was originally anti-aliased into a solid color background. Yick

Oh, just noticed it's for topic headings and forum headings too. Wunderful

I upped the size by 2 pixels.. that seems to have gotten rid of the aliasing effect for the font.