Yes, he's innocent until proven guilty. That said, we also live in America, where we have the right to think whatever the hell we want. Telling people to "STFU" is just as ignorant as presuming he's guilty, if not worse.
You see, I think he's guilty, simply because of his prior record (he wasn't convicted, but the out-of-court settlement is pretty ****ing). He also does a lot of things that I think are despicable (dangling a baby out a 5-story window for example). I have no sympathy for him whatsoever, as he's brought a lot of this hate on himself. He's not a relevant performer in the world anymore, so he does more and more outrageous things to get attention.
While I do think he's guilty, I think he'll get off simply because he has enough money to buy lawyers who will wear out the prosecution and win the case. OJ did it, despite pretty clear evidence to the contrary (although the police really screwed up with the way they handled the crime scene).