I have some code up on my repository:http://svn.gib.me/public/supermeatboy/
(haven't yet committed new stuff I've worked on)
I've worked on some of the file formats the game uses (tile palettes, images, etc). Is anyone actually interested in being able to create files in these formats for custom levels / etc? (this would be how I made the first Super Tofu Boy level shown in this video
in Super Meat Boy).