I dunno... it could be mostly just us hardcore gamers... but judging from examples I've seen (aka casual gamers and online gaming), I think Online gaming will be huge.
I don't know any person with a Ps2 and Maden who isn't online... and I know a BUNCH of people with Ps2s who have Madden

(20+ if you are intersted)
Yes but like I said, this generation I doubt it will push consoles... no nobody who is sitting at home who barely plays games will buy a Ps2 for online gaming... but when they do buy an Xbox/Ps2, and get a nice taste of online gaming they will be hooked.
Is it hype that is making me say this? No, because there were enough games online in the past to pass judgement. Look at Dreamcast! Now, before DC, my opinion of online gaming would have been much different.... I had little/no interest.
But that lack of interest only lasted til Sega gave the free Seganet trials... I got a taste of it, hooked even sense.
Online gaming will get bigger and bigger, and once you fall into online games, there is no turning back. Online gaming is just a new way of solidifying buyers. There is now a Microsoft community online, mixed with casual and hardcore gamers... just like there is a Sony Community online.
Next generation, all those guys will flock to the best online console... so online play will be a big feature each console should concentrate on, if not the biggest feature.