This information comes from a screen shot of an ad that was served as part of a test application, so consider that your fair warning that this could be bunk.
Clicking on one of these ads, which touted "iTunes Movies," "iTunes Movie Rentals" and "iTunes TV," took users to a mobile iTunes client. AppleInsider reports that the client "shows what appears to be a work-in-progress video section of Apple's mobile store. Viewers can browse genres and see featured items, but tapping the actual videos themselves produces a notice that the content is 'not available.'"
Could this be a new reality? Sure, it could. It would also be a nice one, though I seriously doubt AT&T would be a party to it. The more realistic situation is that movie and/or TV show downloads would require Wi-Fi to work.
Perhaps Apple will confirm this capability come the WWDC keynote on June 8.