1.2 is now considered stable, and is good. But it's a work in progress ( for now it does what it does well, but it hasn't eons of features ).
Then ( someone bumped this post, so it's time to update something ) other programs with new versions:
Gimp v 2.0
( considered stable ): a lot of changes ( 1.2 was 3 years old ) , downloading now. Also the windows version is now officially supported as well as the mac one ( this one under X as far as i have just read ).
A new discovery:
: great open source compressor with support for zip reading - writing, and a lot of other formats in reading ( Rar, Ace, etc. ), as well as a very good if not the best archieving method, called 7zip.
It includes also a really good file manager for windows that can be configured to emulate the look and feel of explorer and of midnight commander. The only problem is that now it is windows only ( but it works with linux with wine ), but porting to other platforms will start soon.