Hi Matt!
No...that logo's been there the whole time.
The logo isn't a teeter-totter per se; it is instead a fulcrum and lever illustrating the SMF motto, borrowed from Archimedes: "Give me the place to stand, and I shall move the earth". With a teeter-totter, the fulcrum is in the center; you move the kid at the other end, unless he's heavier in which case he moves you. If you moved the fulcrum, the little kid could lift the big kid. Same principle.
Some people think the Simple Machines Forum isn't a see-saw; it is the light-through-a-prism from Pink Floyd's Dark Side of the Moon album cover. That is incorrect. The PF prism bends the light down, not straight through. The logo is, indeed, a lever and fulcrum.
Good question, Matt!
Best,
Dan.