At the risk of sounding bewilderingly behind the times, I was surprised to see no mention of Adobe Connect, and a comparison of what Wave has over Adobe Connect (a.k.a. Macromedia Breeze).
First of all, I am currently serving in the U.S. Army, so I can make this anecdotal claim with a fair amount of certainty: Adobe Connect is a big deal for the Army and is quickly becoming as indispensable as e-mail for a means of collaboration. If a briefing involves a distributed audience, then it is probably going to be a PowerPoint presentation shared via Adobe Connect.
So, what does Wave have to offer that Adobe Connect does not? One thing is certainly the ability to edit documents in real time. But how far behind is Adobe Connect from that? Not far at all, I imagine. I've never tried this, but here is what I think folks could do, in Adobe Connect terminology: a user with host (who wants to modify the document in question) status edits a shared file and then re-uploads it to the Adobe Connect Server. The client application already has a chat widget, so that covers instant messaging.
Want a bot that can participate? There are scripting tools out there - the kind that can automate typing and clicking, and windows script host scripts that can automatically generate office documents from other data sources.
I can see one big objection to my good-idea-fairy inspired commentary, and that is Adobe Connect seems better geared towards one way communication; it works well for scenarios where one person at a time disseminates prepared information, and everyone else listens to what the current speaker has to contribute.
What I am writing to let my fellow slashdotters know, as it seems this might not be common knowledge, is that there is (in the U.S. Army, and particularly the Army in Iraq) an entrenched product that comes close to what Google is offering. Something that my fellow slashdotters already know, but that bears repeating at this juncture is that product entrenchment goes a long way to staying entrenched, and a product that is entrenched in the U.S. military has a good foothold in the climb to becoming a standard.