PackageKit is this amazing idea of having a tool for managing packages that works identically on every distribution. It’s got both a GUI and a command-line tool, called pkcon. Check out some screenshots. To reach that goal, it has to actually work on every distro.
Wouldn’t it be great if PackageKit worked on Gentoo? You could make that happen! Three major package managers work with Gentoo: portage, paludis, and pkgcore. Working on this as a Summer of Code project means you’d write a PackageKit backend for one of these package managers, in the process learning the API of each and working with PackageKit founder Richard Hughes, me, the developers of one of the package managers, and the broader Gentoo and PackageKit communities.
Three potential applicants have already talked with me about this, so space is limited. You can reach me by email or on IRC (irc.freenode.net/#packagekit as dberkholz) if you’d like to talk about your ideas.