Well, it depend what kind of online you are talking about
Yes, it will have modems right at launch, on day 1, so 3rd party developers like sega can make a game online using their network.
But if we're talking about nintendo's OWN network (3rd parties cant use it, far as i know, unless they pay a licensing fee, just like sega, sony, MS) wont be ready till Q2 2002. Basicly, the batch of games we'll see during summer or fall from nintendo will be online.
Perfect dark 0 and thunder rally are good examples of games that will be online in 2002
Btw, Ms keep talking about their online strategy to be so ahead of competition, when in fact MS doesnt plan to have an online game until 2 years, yes..2003. They'll just let 3rd parties build their network and use the broadband connect, not really ahead of sony, nor nintendo.