One interesting thing I've observed from building jaxb 2.0 (from source) is that if I set up a project in Netbeans (4.1.x) or IntelliJ (5.0.x) or just build it directly via Ant (1.6.5), the source code compiles just fine. But if I set up a project in Eclipse (3.1.2), a lot of source codes with Java 5 generics constructs are marked as errors by the IDE! (Example: ElementInfoImpl.java under package com.sun.xml.bind.v2.model.impl)

This seems to indicate that as jar as Java generics goes Eclipse is not quite up to the task yet.

I am not sure if they have anonymous cvs access, but if you subscribe to www.dev.java.net (which is free), you can check out the jaxb 2.0 cvs source tree and see the IDE differences (simply by importing the existing project config files set up for various IDE's including Eclipse, Netbeans and IntelliJ):

cvs -d:pesrver:yourid@cvs.dev.java.net:/cvs co -d jaxb-ri jaxb2-sources/jaxb-ri

I filed a bug report to Eclipse https://bugs.eclipse.org/bugs/show_bug.cgi?id=125956.

Update on 23Feb06: I received a email from Kent Johnson saying he has this bug fixed in Eclipse 3.2M6. Thanks Kent!