Be warned, this is a strange list...

Portal 2
Dear Esther http://dear-esther.com/
The Fancy Pants Adventures (PSN & XBLA)
Black Mesa Source http://www.blackmesasource.com/ (we can only hope)

If Potato Boy becomes fully unlocked editor character....

I have dibs on chapter named "Meat and Potatoes"

Potato boy seems even faster than Meat boy. I could be wrong, though.

Anyone know what date it is by any chance....

I am seeing the editor and a few chapters being released in April sometime, but days?

Take all words with a grain of salt today....