Wouldn't it be funny if this was exactly what google intended when they shut it down? Surely it helps Wave and future products if a bunch of engineers start building expertise with this type of tech.
The hard bit is getting people to use it.
I wrote a fun multiplayer drawing applet (Java) back in 2000, but no one used it :( sob. Actually a few did, it was fun anyway :) One of my points is, this technology is nothing new.