I agree. Terminator 3 has already destroyed everything that was good about the terminator movies. I don't see how a fourth can do any good. Leave it at 2, and pretend three never happened. That way you have an abigous ending, and the hope that 2 gave for the future. Otherwise, all the actions of the first two are almost pointless.
As for Star Trek 11, it depends on what cast they go with. If they do Star Trek: Enterprise as the cast, it will bomb. That show had few fans, even amoung the hardest-core of trekkies. Another Next-Generation movie can work, if you could get the cast back, but I think that they have all said they are through with Star Trek. So the only way to make it any good, that I can think of, would be a Voyager movie. Honestly, I never really got into DS9, and so I can't really comment on a DS9 movie.