21 May 2012, 14:11
Nah, there's still quite a few different accents - for that matter, there's several just in the northeast - I can think of the Boston and New York accents right away, and then there's other accents here and there.
There are the upper midwest accents (which sound similar to some of the rural Canadian accents), the Texas accents, there are a few rural midwest accents, the generic southern accent...
All of those aren't assimilated into the default "American" accent, which is really more of a southern California accent. (Interesting thing about that accent, though, due to the exposure to American media in Canada, I've read that the Canadian accents are much reduced in Canadian youth, and they have a blend of their local Canadian accent and the southern California accent.)