Mark Overmeer gave a talk with support from myself at YAPC::Europe 2006 about cpan6, the design so far is the result of a collaboration between Mark and myself. The talk was generally well received, and during the conference we have heard many more peoples' concerns. The good news is that there were no new requirements that didn't fit cleanly in the design, in fact it gave some people lots of ideas. I think I can say that we have support for the general direction of things, and now we can open up the debate widely, and start implementing pieces.
I invite people to join either the pause6 mailing list (for infrastructure discussions) or the cpan6 tools list (for client-side installers and upload tools).
The earliest task will be looking at the big picture, and seeing which pieces are the low-hanging fruit that we can write tests for straight away. I'll start the ball rolling after we have a few subscriptions.