Don't hold your breath. We haven't revisited the mobile version of Basecamp since we released it and haven't started any other new projects based on Cinco.
I'm not sure when/if we'll have a chance to get back to it.
I think I may have asked this before, but would you mind describing a bit about how you foresaw Cinco coming together? What would it have provided on top of Backbone.js + Stitch/Sprockets?
Surprising. Mobile Basecamp became a lot faster a few months ago. I thought that it was because of code improvements, now I'm guessing it is due to iOS 5.