.com will always be king. If anything, I see this as inevitable, and a good thing. Increased supply for the the same intrinsic demand will just mean lower prices across the board once the novelty wears off.
I do agree with you; .com will continue dominance, but I think URLs will become increasingly meaningless because of the "Chrome-all-in-one-search-and-address-bar" effect. If I want to go to facebook I just throw "facebook" up in the omnibar. If I've never been to the site, it'll be the first search result (after a couple ads, of course). Otherwise, it'll auto-populate and I can hit enter after I type "fa". No (understanding of) URLs needed. Same with any other site. I'd wager a guess it this will be the case increasingly often as time goes on that a URL plays almost no role in navigating to a site. Especially for 1: people who are growing up now and just figuring out the web, for whom there's little point in learning about URLs, and 2: older people currently using the web who are unfamiliar with what a URL is. I prefer Firefox and keeping my search box separate, but it's hard to deny that the omnibar is a great solution to make the browser much easier to use for those who are dissuaded from using computers and the internet..com will always be king