A plasma will always have a brighter image since the source of the light originates at the panel. So, while you won't get as much puch with a front projector, you will get as much punch, if not more, than what you get in a movie theater.
For about the same cash as a good 60" plasma, you can typically get a front projector that will run at 100+ inches. That's about 3 to 4 times the surface area and the quality of the video will be phenomenal.
In a perfectly dark room that doesn't have white walls, and uses dark furniture you will end up with a simply awesome image. Since your eyes will adapt to the light on screen then you will have an image that typically looks 'plasma' bright, but is in fact much dimmer. Yet, a good projector will have as accurate of colors and as good, if not better, of a contrast ratio. The display will still be 1080p resolution, so if you are sitting at 1.5x the screen width of your 60" display, you need to be at 1.5x screen width of the projection screen for the same appearance to your eyes.
Don't believe that a projector can appear awesome, check out these 100% unretouched photos...
http://www.avintegrated.com/lighting.html
The first image you would probably swear was from a plasma... but none of them are.