I agree, except there are some exceptions in that a "generic" dot us name, or "pertinent" names (like major cities) will do better than average here in the US anyways--which does limit it.
The same could be said for the other two, .biz and .info. The best names to have in each TLD will be generic and be a perfect match. You could throw dot pro into this mix as well. Eventually this domain will be let out of it's box, and certain domains will immediately do well (ultra premium generics).
Ultimately, a TLD must begin to reach a certain awareness (and bonifide usage) to gain a foothold on the internet landscape. I think you will see .biz and .info advertised heavily in the next few years.
I'm already starting to see .biz names (locally) being advertised. This guy is actually buying "air time" to promote his site:
http://www.autovenue.biz . As far as I can tell, he doesn't own a car dealership, however his ads on TV makes it seem like he does (interesting idea--don't laugh a friend of mine bought a car, sight unseen via the internet). In the ad it shows his "AutoVenue.biz" sign outside what looks like a car dealership!!
additional info on this site: It appears he has a physical location of just sales staff, that help you find cars via the internet.