i for one would be interested in an 80" to 100" PDP.
(A) some architecture (like my den) simply can't support light management properly.
(B) some architecture and some families can't support the two-part (projector, screen) setup of a projector - for a variety of reasons (kids, no ceiling mounts, etc.).
the reason why PDPs might be a big win long-term in the market is their simplicity. projectors are not simple. if the price point comes down, joe six-pack might buy a PDP. no way joe six-pack is going to line up around the corner to buy a projector and a screen even if the pricing is identical or better - way too much of a hassle.
from a mass market perspective, PDP is only different from tube TVs in one way: price. the mass market is very flexible about image quality (oh lord - go look at 27" TVs at Best Buy - yuck!). PDPs can sit on a table with feet just like the tube they'd be replacing. it's an easy transition to make. not so with projectors.
finally PDPs can be made arbitrarily large. there are engineering chalenges, but they can (and will) be overcome. (i) heat management, (ii) computational power, and (ii) glass/medium strength. someday i believe that high-end theater may be the applicaton of PDP substrate (?) onto an entire wall of your den/theater. when it's turned off it'll be a black wall (maybe they'll figure out how to make it white). when it's turned on it'll be video, with pixel sizes 75% to 50% what we have today. hundreds of millions to a few billion pixels.
obviously some serious engineering has to happen first

, but i think it could happen.
doody.