(I think I've broken Firefox's cookies, it keeps making me have to log in manually)

This would only be feasible with an insanely high-powered internet connection, or a small local area network.
The reason is that server farms (for logging all the info) would become slower as more and more servers connect. Now, that usually wouldn't be too much of a problem, but with hundreds of thousands of prospect players out there, if even 25% of current CC users were to go on to the service RIGHT NOW, (besides the point that there is none yet >_>) a typical indie server farm (of about, say... TWO computers running the lot) would be under considerable stress, because most servers run slower than similar normal computers in computer processing (data transfers are a different issue). Now, if there were three computers in the farm, and 8000-10000 people logged in at once, it would be close to crashing.

So, the most viable option would be to only have a local area network came system, because it's pretty much proven that groundlines are faster than wireless systems.

Good day.

Hey guys, don't forget tetris style verses.

As in do something to one side whenever the other guy does something else.

Like for every unit killed, another one spawn on the other guy's side.

Actually the above is a good idea. Wouldn't have lag, as the only thing being sent is kill totals.