I did not find this issue open, so I am creating it.

The latest snapshot creates a noticeable FPS drop. Before I could play without lag on short distance, but now I lag no matter what my view distance is. Dinnerbone mentioned that turning off smooth lighting might help and it does... it increased my fps from 10 to 25. However, who really wants to play this way? :/

Playing on SMP on a server with the latest snapshot.