EMF has had an undocumented/unmarketed Maven2 repo for about 4 years now.
All you need is to take an update site zip, unpack it, rearrange the folder structure, and rename the jars. Then you create little XML files called .poms to describe the jars in the tree, and Maven-aware tools can read the tree. It's fairly trivial. http://download.eclipse.org/modeling/emf/emf/maven2/ is the URL, IIRC. About once every 2 years someone asks about our providing such a repo, and I give out the URL. Clearly not a huge demand for it.
One might argue that creation of such a folder structure is in the purview of Athena's publishing scripts, which today eases the process of copying your bits to download.eclipse.org, then unpacks your Update site so it can be scanned by p2 rather than downloaded as a single archive. It too is fairly trivial. I would not be adverse to converting my existing shell script for the EMF repo creation into a generic Ant script for use by Athena users.
Frankly though, I think it would be more valuable if the m2eclipse folks added support for reading/converting p2 repos. Publishing yet another file format would require another release-train-like workflow (we already have two: EPP and buckybuilder for Galileo) and more people maintain it. Even if every project published their own maven repo, we'd want for the sake of ease of use to aggregate them into a central place for easier navigation and discovery by maven tools. So, like with Ganymede, we'd have each project's bits copied to two places on disk for each build. (Galileo used composite repos to POINT at project repos rather than copying them saving tons of disk space and CPU cycles. AFAIK, Maven does not support this concept, but I could be wrong.)
There's also another benefit to having tooling to support converting from p2 repo to maven2 repo: the aggregate repo could be housed at apache.org and suck THEIR bandwidth and support resources instead. Thus just as Eclipse.org is upstream from Fedora's Eclipse project .rpms (which are upstream from Debian/Ubuntu's .debs), Eclipse.org p2 repos could be upstream from Apache's Maven repo(s). After all, Apache already collects maven artifacts for non-apache.org projects to facilitate the use and adoption of maven, so this is entirely in line with their standard operating procedures.
Posted from Blackberry using Opera Mini, by the side of Shawnigan Lake, Vancouver Island, BC