I've done it once. I think done well it produces some very cool photos. Done badly it's quite awful. Again, I'd refer people who are interested in this to the
PFRE (that's Photography For Real Estate) Flicker forum, and to
Larry Lohrman's blog, where there's a lot of discussion about HDR and other technique, as well.
The biggest problem I see with (most) HDR images is the "muddiness" in the midtones. It's hard to describe, but something is slightly wrong in there. And of course, outdoors, if you have moving clouds, or leaves trembling in the breeze, then you get weird blurry effects.
So I'm not terrifically interested in it, but I do think it's going to be a big thing, and as people get better at managing the process, and the software evolves, I think we're going to see a lot of it.