I'm now trying to figure out the best way to incorporate these libraries into a Java-centric paradigm. Joe Walker has done some really great work with his DWR project, but I'm not quite sold (yet). I'll have to find out for myself how hard it is to take DHTML written for PHP or Ruby on Rails and adapt it for use with DWR.
I'm also very interested in finding out how hard it is to incorporate sophisticated DHTML into JSF components. If anyone has come across good examples (particularly JSF components packaged for Java Studio Creator) please let me know.