I am posting this on my xoom BT tethered to my Droid 2 on 2.2 froyo. Once BT connection is established, there is an option under BT settings on your xoom to tether. Just tap that and it will establish the connection. Easy!!
Edit: just saw you wanted to make sure it still works after the update my bad!
For me its more stable than the ROM I was on and the speeds are faster. It doesn't cut out the 3g radio like it used to for me. Since I am having wifi tether issues this is nice. It was the exact opposite for froyo
I wouldn't wait for this to be released. From past experience with Blackberry and Verizon, I can see Verizon rejecting every update from here on out. DX2 is almost out people. Be glad we got this leak. And lets pray I'm wrong about the updates. I have been before.