An apparent delay in the approval of SlingPlayer’s release on the App Store, coupled with unconfirmed reports that AT&T isn’t keen on seeing the device make its way to the iPhone, has led to speculation that the wireless carrier is seeking to have the software rejected in its current form.

Formally announced at January’s Macworld Expo with an expected release date of March, the SlingPlayer Mobile application promised to allow iPhone users to stream live television over WiFi or 3G by tapping into home TV setups equipped with a Slingbox. A built-in remote control function would reportedly allow for channel surfing and DVR setup.

Now, a new — albeit unconfirmed — report is fueling speculation that something may have gone awry during the application’s approval process. The report is citing an unverified source who claims that Apple plans to deny the application in its current form because AT&T has expressed concerns about its potential to saturate its 3G network.

Assuming the claim is accurate, Sling Media may need to alter the application to function along the lines of Skype for iPhone, which will operate over a WiFi connection but not 3G wireless networks. Such a move would obviously curb the appeal of the Sling application, making it inoperable more often than not. The claim is dubious, however, given that a version of SlingPlayer runs on several other AT&T devices like the BlackBerry Bold.

For its part, Sling Media has said that is has received no official word from Apple on the status of its submission. It’s not in as of right now anyway.