Assembla isn't free for closed-source projects (http://www.assembla.com/plans?locale=en) unless there's a hidden plan. Apparently they made the change back in 2008 (http://blog.assembla.com/assemblablog/tabid/12618/bid/6986/R...), but this article was written today which is confusing. Am I missing something?
BitBucket (http://bitbucket.org) went free for private repositories a while back and recently added git support. That might be a better alternative today.