Is 1080P important? Yes...and no...

One of the most frequent concerns I get from customers is over 1080P. Will the display be 1080P? How about the sources? Will everything be HDMI 1.3 cabled? 

To the last question I say, yes, all your cabling will support HDMI now or in the future.  But to the rest?

It depends.

1) How important is image quality to you?

For under $25K projectors, I think the gold standard of image quality is still the Sim2 3CX.  I'm fairly impressed with the new Sim2 1080P 3-chip unit but the 720P triple chip C3X beats out everyone else in image quality.  Do you sometimes see pixel structure when up close? Yes, but color quality, black levels, color accuracy are so important too.

2) How far away do you sit?

At 10' for 50" display or 12' for 60" panel, your eyes cannot see the difference between a 1080P and 720P image.

3) What are your sources?

All HD is not equal.  The broadcast compression used, especially on HD material, lowers it's quality to the point that the artifacts sometimes are more visible on 1080P than 720P and a more pleasing image is rendered by the lower resolution device.  Take a look at the following images: DirecTV broadcast version vs. HD-DVD.  Look at the rock in back.

DirecTV 1080i

HD-DVD 1080P

Many 720P displays will do a better time with the DirecTV broadcast than the 1080P sources.  Audiophiles are familiar with this - there are quite a few fantastic 2-channel audio systems that sound awful with lots of recordings because they reveal so much.