I have faith in Rodriguez. I loved Desperado, Planet Terror, From Dusk Till Dawn, Sin City and his story in Four Rooms. He has a great ability to do more with less. He doesn't need to spend 100 million dollars to make a movie look good. I bet on his 30-40 million budget the movie will look like 100 million was spent on it.
That said, there always is a bit of reservation with any Alien/Predator movie. I had high hopes for AvP:R, but after seeing the trailer, I knew the movie would be trash, which is exactly what it was. Even if they turned the lights on, it would have still been trash. They basicly took all their favorite bits from all the alien and predator movies, and redid those scenes (poorly) and cobbled a poor story around it centering on a pizza delivery kid.
Apologies for the rant... AvP:R was just so.... bad.
Just from looking at the teaser for Predators, and hearing Rodriguez speak, I am more optimistic. It seems like Fox won't be breathing down his throat since it is being made at his studio - that is a very very good sign.