Interesting ... I"ve been seriously thinking of the same theme for 2013. Our haunted house is in our garage, and we've been doing this for about 5 years now. We've always done the old Universal stuff ... the Mummy, Wolfman, etc.
Time for something new!
I can fit about 4 - 5 "rooms" into our garage. I'd like to build a facade so that it looks like a UFO crashed into the side of our house, and the facade would also be the entrance & exit into the UFO. I'm not sure how this would be built exactly though. I guess we'd have to have some kind of construction resting just outside the garage, along with the spaceship's tail up against the garage's side of the house.
It'd be cool to have a control room or bridge area, with several panels of blinking lights, displays, etc. I know little about electronics though, so this will be interesting to learn. An alien scare would work well here ... maybe someone in an alien costume suddenly appearing from behind a sliding door.
Using a dot room would fit well with this theme ... maybe another person got teleported, but didn't quite make it all the way. Plus, a dot room is a really cool illusion with a minimal amount of effort.
Other than that, I have no idea what else to add.