Another suggestion for a Google SoC project: semi-automatic removal of unused software.

Installing extra software is very very easy with Debian. However, you’ll just fill up your harddrive, and actually keep lots of software around you actually do not use.

It would be nice to have a tool (maybe functioning similar to popcon?) that monitors (e.g. via atime) which applications you actually use, and suggest others for deinstallation. Of course handling dependencies right (i.e. if you chose to install the GNOME meta package, it shouldn’t suggest to remove standard parts of GNOME even if you don’t use them).

Well, I don’t know what others think, but I would like to see that done, and I can imagine this being an interesting SoC project. So go for it!