The difference between the Nexus One and Nexus S is that when the Nexus One came out not only was it the best spec'ed Android phone you could get, but it would be the best spec'ed for some time.<p>While I think you can argue that the Nexus S is the best spec'ed Android phone today (and I think there's an argument to be made against it, with phones like the Epic 4G that includes 4G support, while the S doesn't have HSPA+, a really odd omission), it seems pretty clear that this will be pretty short lived... we've already seen leaks of phones like the Optimus 2X that will be out shortly