Pick a subset of Debian that is the core. Release the core only when it's ready, which should be more frequently than when all of Debian is ready. For the other stuff, users would have to [FIXME: do what?]

Pros:

Cons:

Other thoughts: This could be combinated with the ReleasePerSubsystem model, core would simply be a subsystem in this model.

See ReleaseProposals for alternatives.