Sling Media is now listed as a developer in the App Store, but the fate of SlingPlayer is still unknown.  This essentially means that Sling Media can now sell officially sell apps, but there is only one app of consequence to Slingbox owners. SlingPlayer for iPhone was submitted for review back in March, but Apple has yet to either approve or decline the app.

It's not clear if this has any bearing on a possible approval forthcoming, but we'll take this as progress.

[SlingMedia forum via iPhone forums]