I am very happy with Eclipse 2.1.1, but Eclipse 3.0 M4 has interesting new features including a new browser plugin, so I tried it today.  Well, I didn't get very far into it.  IDE itself feels pretty solid but plugins I use were not quite up to the challenge.

Several plugins I use require EMF and XSD plugins, but those plugins are hardwired to Eclipse 2.1.1 for some unknown reasons and were causing configuration problems.  Patching the offending dependence tags in EMF and XSD features.xml files didn't fix the problem.  Since I need those plugins and don't have time to fix the problem myself, I can't use 3.0 M4.

BTW, Eclipse 2.1.2 will be released end of this month with at least 54 bug fixes.  EMF and XSD will still cause problems, but I expect them to be updated fairly soon for Eclipse 2.1.2.  Eclipse 3.0, on the other hand, won't be released until well into next year.