I just tested the new features on the launcher update. I played Minecraft 1.2.5, before i played my lauglages was set to Danish (Dansk) and had my resource pack on. After playing i closed the game, Started playing Minecraft 1.6.2 and i once again selected Danish (Dansk) and the text was in a incorrect size! I closed the game and playes Minecraft 1.5.2 and anything was normal.
I deleted Minecraft 1.6.2.jar and re-downloaded it and it happend again