What's wrong with a github account? Give them some love. Their private option is cheap. Over all once you start using github it's hard to go any other route anyway.
Anyways, since git is decentralized, why go through github? What about pulling/pushing between the user (or any arbitrary git client) and pagoda box directly?
Edit: I watched the screencast, your deployment process is a bit different than I expected so I guess using github is probably a good idea.
So as much as I like everything else about Pagoda, if they're forcing us to go github route with no alternatives, I won't be checking it out.
I also disagree that it's hard to go any other route. Gitweb works great (the interface is better than github's imho) and it's free for unlimited public and private projects provided you already have a place to host it (i'd best 99% of HN users do).
It doesn't support Mercurial. I use BitBucket, on which private repositories are free (and I don't have to use git, which is a plus).
Supporting only github means I can't use it. Unfortunate, because their stuff looks cool.
I'm sure if you really wanted to use Pagoda, you could use the http://hg-git.github.com/. Or you could just sign up for a free Github account (free seems to be a requirement for you, and these days with the state of the economy I can definitely relate. although no free and private as you mentioned) and learn git, which is a joy to use, and blazingly fast, which is nice for cloning large repos. Personally, I use Heroku and prefer Ruby to PHP so I don't feel compelled to try Pagoda, but I could appreciate the work that went into the site, and the backend. Impressive.
I can afford a Github subscription. It's not that much money. It's just completely worthless to me.