Apple's yearly developer conference should see iOS 8, OS X 10.10, and likely some hardware.
SlingPlayer Mobile for iPhone Release Imminent - Wi-Fi only
In addition to full support of current Slingboxes (PRO-HD and SOLO), legacy Slingboxes, which include the Classic, AV, and TUNER, will work with the application but will not be officially supported. However, the application will be limited to streaming only over Wi-Fi connections.
Previous demonstrations of the application by Sling Media had promised EDGE and 3G support, however it appears as though this will not be the case. Pricing is said to be set at $29.99.
This information has been confirmed by multiple sources.