Only our PR Department can issue an "authoritative" statement to such an effect.
So where what I can say, which is not considered 'difinitive', but should sufficiently answer your question is that while it won't downconvert to 1080i (since the panel is a 1080p native resolution, and such a process would be redundant on the 6-Series), additional processing WILL happen in the form of upconverting the picture to 120Hz. That's more of a benefit (enhancement) in the eyes of most people, however, there isn't a way to turn that 120hz upconversion off.
I hope that helps.
What I need is an authoritative statement that a pre-processed 1080p signal will not be re-processed in any way, such as converting from 1080p to 1080i and back again, which I read can happen. I wish to use an OPPO Blu Ray BDP-83 player, and I want its 1080p output to be monitored and displayed without ANY further processing.
My other HDMI source will be my HD cable television provider, which at present provides 1080i as well as Standard TV channels, which your LN52A650 can subject to whatever processes it wants.