Just to muddy this topic some more --

The newest, but separate, things in road bike tires and wheels are tubeless tires and wide rims.

The people who ride tubeless are saying that they can run lower pressures (like 90 psi instead of 110) and gain comfort and cornering grip while not losing efficiency or rim protection. They also are having fewer flats, probably mostly due to the sealant used, which both seals the bead and seals potential flats.

Wider rims, as they relate here, are as wide as the tires themselves -- about 23 mm instead of 19 mm like most road wheels. It's enough of a difference that the tires' sidewalls don't bulge out anymore. Owners tell of the same benefits as tubeless users, especially when it comes to fewer pinch flats, more consistent handling, and a nicer ride quality.

I think both of these approaches make sense. Car tires have been tubeless for a long, long time, and their normally straighter sidewalls don't give a squidgy feeling to handling. It's just that tubeless road bike tires are a recent development due to 1) sealant technology caught up with high air pressures; 2) change in cycling can be glacial sometimes; and 3) manufacturers need a New Product to sell. I haven't done either of these yet, though, mainly just because I got some nice regular wheels last summer.