IMHO this new extensions idea make some sense ....but only in case, where registration price is high enough, to limit interest to serious companies and application process is screened. It could help big corporations, if they really, really want their separate domain and/or run multilevel sites (
.ebay,
.apple,
.microsoft,
.bmw,
.audi)
It will be more like .travel / .pro / ,museum (by the way... personally I never use those extensions)
For the regular players, it will mean nothing. People will always type .com up to the point where actual PR and quality of SEO will be more important than domain itself.
I don't see situation where
chicago.com will be replaced with for example:
start.chicago or
home.chicago
How about longer words like
classifieds or
realestate ? add prefix to that and you have a lot of typing :D
Personally I would be scared more about growing role of search engines than those exotic ideas made by ICANN. You could have
PIZZA.com with PR1 and still loose in search engine with better developed
NyPIZZA.net with PR7.
The time is coming where actual content will determine the value of the domain, not a name or extension.