Leominster to be specific. Noticed it this morning around 4:30 as I was leaving for work. 8-10 Mbps so far. I assume it will get faster as we get closer to the "official" launch? Gigantic increase from their crappy 3g.
Very cool, but with this being a Sprint thing and not just a Nexus thing, you may want to post this in the Sprint forum: http://forums.androidcentral.com/sprint/