Nope, it is a mystery.

plurk has IM support?

Yes! It's under "My Account" Not sure how it works, but it's there in theory

I got it working with google talk, but it doesn't seem to follow people & terms a la twitter

So it's update only over IM? That's a bummer.

in theory you can respond to plurks, but I haven't gotten any updates with which to respond to (including this one).

oh: follow via IM is turned off by default. go to "My Friends" to turn it on for specific users.

Ahhhh. Right on.