It looks like it is browser only. We are currently looking for something like this that also has a standard protocol like XMPP. Actually all we really want is for Google Chat to support rooms for apps/business users.
You could use Candy (http://candy-chat.github.com/candy) as a nice web UI for XMPP MUC (Multi-User-Chat). It supports basic features but is easily extendable through plugins.
The one thing that has the lowest utility is a web based interface to chat since it essentially doesn't work well in the background in the same way as an app like Pidgin does.