
If AT&T did in fact ask Apple not to add the SlingPlayer App due to network data traffic concerns, then Sling may have to do the same thing as Skype and limit the application to Wi-Fi only. However, there is also speculation recently that AT&T is working on its own mobile video technology, and it has silently changed its terms of services basically prohibiting the use of services like SlingPlayer on its network.
Of course, if AT&T doesn't manage to retain iPhone exclusivity, then Sling may have nothing to worry about soon.