Choosing the wrong extension can put a site at a severe disadvantage with search results. Google doesn't apply the same weight to .info, .us, and lots of other extensions. I don't yet have an opinion about the new extensions.
.com. .net and .org still rule the search results. I sometimes see other extensions with good rankings, but it is rare. Just something to think about . . .
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin