From the Dish Network site:
IS MY PHONE COMPATIBLE? iPhone/iPod touch | Android | BlackBerry | Window Mobile
iPhone/iPod touch
SlingPlayer Mobile is compatible with all versions of the iPhone and iPod touch. You will need to purchase SlingPlayer Mobile from iTunes App Store and be reimbursed by DISH.
Please note, only one SlingPlayer Mobile App credit per DISH Network account.
Android
SlingPlayer Mobile is now compatible with Android mobile phones, and is available for purchase in the Android Market. A separate DISH Remote Access application will be available for FREE in the Android Market in the near future. Please check back often for updates on when the FREE DISH Remote Access application will be available.
BlackBerry
Many BlackBerry smartphones from AT&T and T-Mobile are compatible.
...The question is how long it will take. I am sure the wait will be painfully long. Unfortunately it looks like we will never get free "Sling" support, only free remote access