I kinda think so. I know a lot of people who would just rather wait for DVD than pay the elaborate cost of movies theaters (my experience renting is always cheaper). This is getting even more of a problem with larger screens and better sound as I didn't spend an arm and a leg on my setup, but I also have better sound than my local theater.
Granted, 3D movies can only save movie theaters if the technology to bring that into the home doesn't develop too fast for it to be really profitable in theaters.