The first thought that came to my mind was that it was for security. Why else would a heli circle for hours on end on Disney property? Security. Or maybe they're filming for the next Soarin video.

I didn't feel the need to report anything. The thing was so darn loud, it was hard to miss. I assumed Disney was well aware of the heli(s).
I wouldn't let this affect your decision at a resort. Note that we were staying in an area very close to DS (I think the heli was mainly flying over DS); the other sections of SSR wouldn't be affected. Not to mention, previous posters mentioned that there was heli/plane noise over the Boardwalk... I should also tell you that we experienced constant heli & drone noise when we were at Aulani, but we were there when they were filming American Idol and they needed to do what they needed to do to keep us all (celebs, non celebs, guests, non guests, audience) safe. I applaud Disney's efforts to keep us safe. At the end of the day, the heli/plane noise didn't make or break our vacation.
Altho that being said, SSR is now one of my top fave resorts post-reno and proximity to incredible DS. I need to stop being a walking ad for SSR on the disboards. So yes, LPnerd - stay away! It's terrible there. SUPER noisy & those darn helis!