ALL TEXT mixed and screwed up

I started Minecraft 1.6 pre-release as usual, when I noticed that ALL THE TEXT in the main menu was mixed up and weird.

I tried to change language from Swedish to English, but it stayed weird. When I entered a server, all text in the chat was mixed to! I entered a World and all text on signs, animal names (above them) and items in my inventory was mixed!

I closed the launcher and waited a minute. but when I tried again it stayed with weird and strange text...

I have NO idea how I triggered it. And it disappeared when I downloaded the launcher again!