I think the point of the above comment is that companies are already on board with iOS. MLB already has an iPhone app that streams video. If an AirPlay API is added, MLB releases an update and BOOM! Your TV now has baseball diamonds* .

The great thing would be that you have video on-the-go all the time, and you now have the additional option of viewing it on a bigger screen at home. It'll be hard for content providers to say, we're providing the video to users on the iPhone but we don't want them to have the ability to see it on their TV.

*Memes not required for API compatibility.