I really don't feel this is a good fit. Steam is not particularly great software, it's just one of the best ways to get games onto your machine. It has a lot of competition in the general software market, and plus it doesn't really feel like we need another one.
What really kills it for me, though, is that Steam's model just does not fit software. Want to edit a document on your PC, but left Steam open on your laptop? Well, you've got to walk over to your PC and log out first. That's a (barely) acceptable trade-off for games, but for productivity software it's a ludicrous proposition.