This looks really cool. I worry that apple will push a system update that breaks AltStore in some way - it seems fragile. That said, I think iOS sorely needs competition in app stores. There are open source apps that aren't available through Apple's store because they violate some guidelines (thinking of Kodi formerly XBMC, "true" Firefox based on gecko, not webkit). But that's just what I want out of it.
On a side note, I wonder what state apple's app store is in with regards to antitrust. It seems like a no-brainer that the app store is monopolistic given that Microsoft couldn't get away with bundling internet explorer with Windows. Maybe AltStore will be Apple's ticket out of some future lawsuit.