From Engadget:

We had a feeling it was coming any day now, but now we have confirmation that Sling won’t be leaving iPhone and iPod touch users in the lurch when it comes to streaming TV to their devices. The bad news is the software they showed us was pre-alpha proof-of-concept, and their whole situation is hamstrung by the fact that Apple hasn’t officially accepted them into the developer program yet. So what we’ve seen is basically an app developed out of bounds for jailbroken devices — thus it goes without saying that Sling won’t be releasing it until they can do so legitimately. But assuming all goes well, they do intend to get it out the door by sometime this fall or winter. No word yet on the Android release. Video of the app in action after the break.

Read more here:

http://www.engadget.com/2008/06/08/sling-announces-proof-of-concept-slingplayer-mobile-for-iphone/