Ah! Looks like you got a free subscription to the blind-as-a-bat version of TFL!
That didn't happen on our side. Did you change anything in your browser? Check to see if your text size option has changed from a normal size to "gargantuan". In both IE and Firefox, it's under View->Text size. Other browsers should have something similar.
Also check to see if you are using the "vbulletin 3 -- variable fonts" skin found in a pull down menu at the bottom of any TFL page.