I'd worry less about a
bunch of kids, preparing their
revenge over a
percieved slight to their
nation, and more about the involved
governments themselves.
Well, the US isn't terribly likely to hack (er, crack, sorry) a few Chinese news pages to avenge itself. On the other had, you can bet that, in it's ongoing quest to outdo the rest of the world in military might, the US is doing all kinds of research on possible methods of Cyber Warfare--or, more generally, information warfare. You can be equally sure that all the other major world players--such as China--are doing everything they can to keep up to the States.
Halting or destroying information in an enemy nation is bound to be effective, and thus is bound to play a part in future conflicts. It's hard to run a war with your nation shut down....