WebSphere Community Edition: not available until the end of the year
I don't intend to be critical of IBM: I appreciate their Java SDK for the PowerPC architecture, their support of Linux, etc., etc. However, it seems like this early announcement is just to generate some buzz for IBM's purchased Gluecode and perhaps to rain on JBoss's parade.
While I am very happy with my development environment for simple JSP, JavaBeans, custom tag libraries, etc. I would like a super productive environment for use when I want to use more of the J2EE stack. The JBoss Eclipse IDE looks like it may be a possibility and IBM's WebSphere Community Edition looks like another possibility - I think that it is worth waiting for this to sort itself out.
Meanwhile, I find it ironic that my favorite Ruby Rails development system is based on Eclipse (and RDT and RadRails - new but promising, BTW).