Did you try a clean build?
It's not a cocoon cvs; it's copy of cocoon libs into web-inf/lib.
I have the same jdk and for me it works perfectly :)
The second exception you get is due to a change in excalibur-logger.
The logkit.xconf needs an entry for the root category (category
without a name). I have fixed this some days ago in the CVS.
Ah! Did not expect migration issues from 2.1.4 to 2.1.5-dev. Ok, thanks.
Vadim