To give Sun credit, they have put out a pretty good preview release of the new Java EE 5 along with a new tools preview. A couple of things I noticed were BPEL support and UML support. It's also pretty fast. It's got XML schema support like Eclipse along with a WSDL editor. I think its XML support is a little less robust (from a graphical standpoint) than the Eclipse version. But I did find at a casual quick glance that the UML support and the BPEL support were fairly easy to work with. I was even able to import the BPEL generated by the Sun tool into webMethods. It's worth a look.
Here is a screenshot of the BPEL composer:
Here is a screenshot of the UML editor: