A slight clarification ...
Actually, you guys are talking about two completely different applications for GameSpy's networking tools. That's where this confusion is coming from.
GameSpy TUNNEL is for games that have LAN play, but not Internet. Tunnel uses your PC to act like a console, passing the network packets through the internet. This is how Halo works for Xbox, and is how we thought Online gaming would be addressed with GameCube.
The tools GameSpy is making for Nintendo's games have NOTHING to do with "tunnelling". It's going to be full-on internet play, no PC needed. Saying that the "tunnel" will be included on the disc is not at all accurate, since no tunnelling would be necessary at all. Basically, GameSpy is making the networking tools that Nintendo and other developers will use. GameSpy will provide the infrastructure, effectively making GameSpy's network the "Live" service for GameCube. This is what Iwata was alluding to today, I'm fairly certain, and is what the previous press release referred to.
Of course, we're still waiting on something official, but the rumors you've seen bandied about ... this is where it's coming from.