Eclipse 3.4's new update manager P2 seems to dislike the fact that JBDS includes some plugins/features without all their transitive dependencies.

When installing some of the JBT langpacks (still under development) into JBDS, I get errors in my error log (attached as broken.txt), preventing installation. But it's not just my langpacks. The log attachments for JBDS-454 and JBDS-506 both include errors like this one:
!SUBENTRY 1 org.eclipse.equinox.p2.director 2 0 2008-12-02 17:07:38.489
!MESSAGE Unable to satisfy dependency from org.springframework.ide.eclipse.ajdt.feature.feature.group 2.2.0.v200809261800 to requiredCapability: org.eclipse.equinox.p2.iu/org.eclipse.ajdt.feature.group/0.0.0.

https://anonsvn.springframework.org/svn/spring-ide/trunk/org.springframework.ide.eclipse.ajdt.feature/feature.xml
does have
<import feature="org.eclipse.ajdt" />
and according to my .metadata/.log, org.springframework.ide.eclipse.ajdt.feature is installed, but not org.eclipse.ajdt. (This seems to be how springide is packaged on their website.)

The JBT langpacks I'm trying to install don't even cover Spring features, but P2 seems to decide that the Eclipse configuration is bad, and generates a number of errors for dependencies of org.springframework.*, as well as org.eclipse.jst.server_adapters.feature and org.jboss.tools.eclipse.as.tptp. So it's not just Spring IDE that is broken either. See broken.txt for the details.