Re: Mule 2.x Stability
I am using Mule 2.0.1 in production environment for non-critical application. I find it stable in terms that it doesn't crash randomly, have memory leaks or drop messages. That said, there are some rough edges and non-critical bugs/undocumented behavior, which are usually easy enough to work around.
I would recommend that you use 2.0 and save yourself the migration (btw, 1.x code line is more mature, but still far from perfect ;-)
Dimitar