I'm glad to see this service. The Developer's Reference lists http://www.internatif.org/bortzmeyer/debian/sponsor/ as being a place to co-ordinate the sponsoring of packages. Currently it's unavailable to me (down?). Other problems I have with it include: no place to upload packages and it's for "Sponsorship of future Debian developers".
It's a great resource, but "The Debian Mentors Project" takes things a few steps further. mentors.debian.net provides a place to put packages and a chance for people to use the Debian system for uploading packages (dupload, dput...). It also allows for a chance to practice using keys and signing packages properly. Alioth takes things in a different direction. Alioth allows non-Dd's to contribute directly to an active project and provides space to put packages. Alioth can be thought of as a better spot for packages as it doesn't easily allow for apt-get lines. Alioth does not allow for (afaik) the usage of dput and dupload which is good practice for people who want to become a Debian developer. Alioth doesn't seem to require that its users want to become Debian developers. Drew Daniels