I am running 9.0.1 on MacOSXSL and the plugin manager no longer picks up the fact that there are updates available for installed plugins.
This is a really annoying problem!
Some more info: Recently I downloaded and ran the 9.0.2EAP. I had a look at my installed plugins and noticed that I had the python plugin (v2.1) installed. I looked at available plugins and noticed that the python plugin had a 2.5 release but the installed plugin tab did not reflect that it could be updated. This also occurred with the JRebel plugin when I originally posted this.