I installed 2.0.0.CR2, then installed some stuff into it via dropins/ and .link files, but wanted to get updates for those features.

Instead, I got this, which blocks installing or updating anything until the requirements are resolved.

An error occurred while collecting items to be installed
No repository found containing: org.aspectj.ajde/osgi.bundle/1.6.4.20090106083800
No repository found containing: org.aspectj.runtime/osgi.bundle/1.6.4.20090106083800
No repository found containing: org.aspectj.weaver/osgi.bundle/1.6.4.20090106083800
No repository found containing: org.eclipse.ajdt.core/osgi.bundle/1.6.3.20090122141228
No repository found containing: org.eclipse.ajdt.doc.user/osgi.bundle/1.6.3.20090122141228
No repository found containing: org.eclipse.ajdt.examples/osgi.bundle/1.6.3.20090122141228
No repository found containing: org.eclipse.ajdt/org.eclipse.update.feature/1.6.3.20090122141228
No repository found containing: org.eclipse.ajdt.mylyn.ui/osgi.bundle/1.6.3.20090122141228
No repository found containing: org.eclipse.ajdt.source/osgi.bundle/1.6.3.20090122141228
No repository found containing: org.eclipse.ajdt.source/org.eclipse.update.feature/1.6.3.20090122141228
No repository found containing: org.eclipse.ajdt.ui/osgi.bundle/1.6.3.20090122141228
No repository found containing: org.eclipse.aspectj/osgi.bundle/1.6.3.20090122141228
No repository found containing: org.eclipse.contribution.visualiser/osgi.bundle/2.2.0.20090122141228
No repository found containing: org.eclipse.contribution.weaving.jdt/osgi.bundle/1.6.3.20090122141228
No repository found containing: org.eclipse.contribution.xref.core/osgi.bundle/1.6.3.20090122141228
No repository found containing: org.eclipse.contribution.xref/org.eclipse.update.feature/1.6.3.20090122141228
No repository found containing: org.eclipse.contribution.xref.ui/osgi.bundle/1.6.3.20090122141228

I suspect this is the result of the latest Spring IDE features depending on Aspectj / AJDT 1.6.4, which has not yet been published to their update site.

The latest /dev/ update sites [0], [1] listed here [2] do include the 1.6.4 updates.

[0]http://download.eclipse.org/tools/ajdt/34/dev/update/
[1]http://download.eclipse.org/tools/ajdt/34/dev/equinox-aspects/
[2]http://www.eclipse.org/ajdt/downloads/

So, I propose adding these two sites to the JBDS feature's discovery site, and to the JBDS update site's associatedSites.