Conspiracy Theory:
Here's the scenario. It's a setup alright, but not how you might think.
Let's say OJ has been selling memorabilia on the black market to evade the $30-mil-plus civil judgment against him. Maybe one (or more) of the guys in that hotel room that night has been stiffing OJ on his cut. Or maybe OJ thought he should get a bigger share. Whatever the reason, OJ was headed to that room to discuss the situation and somebody in that room was thinking ahead. So, the tape's rolling... "go ahead and cry, OJ... and this little gem goes to the police." A little blackmail between friends, always a nice thing.
But OJ doesn't show up to chat. Instead he comes in with goons and guns. That blows everything out of the water, a very-pizzed-off somebody leaks the tape, and voila-- here we are.
Supporting evidence: the very existence of the tape in the first place shows that somebody knew something was going to happen. Also, OJ has never made a peep about any of his stuff being stolen. That's not the kind of thing that stays quiet.
My prediction: the criminal charges evaporate... look for income-tax evasion charges down the road. That's what'll put him away, where he should have gone a decade ago.
Anyway, my $.02...