I agree with Torhal, we had that discussion on IRC back when I finished coding the first versions, and it made more sense to keep them separated as they are now. The only drawback is the one I mentioned: the packaging issue.
What Adirelle was suggesting is the Ace3 approach - the suite is broken up into several modules (AceHook-3.0, AceEvent-3.0, etc) but they're all contained in the same project. AddOns which use them pull the modules they need directly from the project's trunk via the .pkgmeta file.
IMO the whole datastore modules could have been made a single project.
If you're talking about "a single project" in the same manner as the Ace3 modules are "a single project", I agree. Otherwise, it would be a huge monolithic library that would include a bunch of unnecessary fluff - someone wanting to handle auctions wouldn't need the stuff for quests, for example.