So, DuckDuckgo now has !bang search goodness for Debian packages (!dpackages) and Debian BTS (!dbugs). The BTS search actually launches the "search", while I'd have preferred just http://bugs.debian.org/%s, so that !dbugs src:python-numpy would just take me directly to the numpy bug page, but it's a start. The search engine creator is very receptive to comments, though, and I am sure you can reason with him if you feel most people would find it useful if it is changed to something else; I wasn't sure what the best course of action was, so I haven't talked to him yet.

Here is the full list of !bang searches in DuckDuckGo, and a submission form to request for new ones. Enjoy!