One of the primary frustrations I had with the further awesome Package Explorer was the lack of filtering. So a few releases ago I added the Bndtools Explorer with a filter box.
For example, if you want to see all test projects, you just enter test. However, if you also want to see the cnf project, you enter test|cnf. Since we use the Glob you can use many regular expression features.
Since the Bndtools workspace is cohesive, unlike Eclipse where projects can be all over the place, it was also possible to show an overall workspace status. So I added an icon that shows a completely clean Bndtools workspace (JUnit green, the color we all strife for), a workspace with a warning, or a workspace with errors. This is a wonderful incentive to keep your workspace free of warnings; the ugly orange stares at you accusingly all the time when you leave a mess. And if you have a large workspace,it is otherwise easy to miss you got an errored project, the large red icon is hard to overlook.
If you have errors, you can also filter for error projects, using the :e pseudo target. For warnings, you can use, you guessed it: :w.