Honestly, it would be way to expensive and would be something that we as consumers would end up paying monthly for. Look at TSO (the Sims Online), even a company as large as EA couldn't make that profitable in the long run. Really VV doesn't lend itself to interacting like The Sims did anyhow, so even if it wasn't so expensive to maintain a multi-player game, changing VV to work as one would totally change VV and the end result wouldn't be what we want (and are hopelessly addicted to) anyways.

If you really want to talk to other players while you play VV - download Skype or Yahoo with Voice and get a mic. It's free.

Something that would be along the lines of shared gaming would be maybe being able to package up individual villagers and share them with friends. There wouldn't be any real player interaction, but it could still be cool.