Wirelessly posted (Mozilla/5.0 (iPod; U; CPU iPhone OS 4_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8B117 Safari/6531.22.7)
I personally think that the frameworks for the something like the Mac App Store are already in place in 10.6 (sandboxing, for starters). The only thing that it needs is the app proper.