I'm not too fond of shelters myself, either. As a trail section leader, I've put up with constant vandalism to my signs--- magnify that to shelters. Way too high maintenance.
If it ever gets down to it, though, I'm thinking the most I'd like to see would be something like down in the Everglades. A raised platform to keep your tent floor from flooding is really all anyone would need; a cadillac version would be a chickee--- some kind of a roof, but definitely no walls.
I still like the challenge of knowing where to set up a tent--- my kids say I'm positively anal about it, but I can tell you that in 20 years, I've haven't been flooded out yet. And I have a few stories, like last year's Kissimmee River hike, when the skies opened up over Rattlesnake hammock. My kids woke up in a 3 inch puddle; the ground under my tent, just a couple feet away, was dry <gloat>.
Speaking of the Kissimmee River hike, it's on for February 13-15, 1999. Two groups going in opposite directions. I'm leading S-N, Jim Pace is leading N-S. I've kept the names of those of you who asked about it earlier-- I'll send out some info in January. Anyone else interested, let me know.