- if anti-trust is about consumer protection (kind of a European perspective), there's no basis. You buy an Apple device knowing full well that the only apps allowed on that device are vetted by Apple. That's hardly new. The rules have not changed. Few exceptions have been made, and I bet those few have been framed by the best lawyers there are to avoid any possible contamination. So there's no new event or situation that has consumers losing.
- if anti-trust is about protecting against market manipulation : no one forces any one to be on the App Store. The rules have not changed. Few exceptions etc. Apple does have sole control of the iPhone apps "market" but is that truly a market in the sense of competition law? The fact that it's called "App Store" should not obscure the fact that Apple could as well have decided to provide only their own Apple-branded apps, and develop themselves all of the apps they make available to iPhone users. Instead they chose to let third-parties provide apps under a restrictive set of conditions that include the "tax". Would it be any different if they actually licensed the apps from developers for a fee and resell them on the App Store to end users?