I updated manually from 3.2. I'm not rooted. Poke around on xda and you can find instructions. You'll need a USB flash drive and an OTG cable. I don't see much difference so I do think this could be a prepatory update for ICS.
Ya i just installed 3.2.1 and as of now i see really no difference. Stock browser still reverts to mobile for some pages and web pages seem to loading alot slower as droid-life.com took me about a minute to load. Going to reboot and test again.
Got the update on my Wi-Fi Xoom... I noticed nothing new or different. I suspect it was for some behind the scenes bug fixes. We use the Xoom in our business for one-on-one sales presentations using PowerPoint presentations... it works very well for that. I also demonstrate our web portal which is flash enabled... again, the Xoom works very well and I have had very few problems.