a DVCS that can handle enterprise requirements, very interesting. But let's see how it compares to git/hg/bzr in a week :) The pluggable storage layers sounds like something I would use in my company.
GitHub more-or-less did that when they switched off of Engine Yard (where they were using GFS), but they had to roll their own with RPC calls. That also meant that they had to change Grit, their Ruby git library, to split stuff that had to get executed on the fileservers (where the actual repos are stored) and stuff that can be executed on the server that wanted the information. With pluggable storage layers, they could have changed how they stored the repos without changing their bindings at all.
I think if they aimed it at a git/hg/bzr replacement for OSS projects, they'd fail mightily.
Either way, they have their work cut out for them.