I can confirm that Mojarra 2.0 works on WebSphere 7+. I recently installed a production application with it.
There is one issue we encountered with jsf.js (Mojarra throws an error saying that jsf.js couldn't be found), but I haven't spent time on it yet. I worked around it by extracting the file and including it in the master template, for now.
[Message sent by forum member 'rdean400' (rdean400_at_yahoo.com)]
http://forums.java.net/jive/thread.jspa?messageID=387905