After picking up my Xoom on release day, I've started using it for more and more things... Some of the ways I use my Xoom
1) As an eReader - both in Google Books and Amazon's Kindle (Kindle works a little better. IMHO)
2) My primary information/media intake (twitter, facebook, CNN, Sports Illustrated, washington post, androidcentral, etc.)
3) DVR/Video - DroidTV and Amazon On-Demand Video (through the browser)
4) Productivity on the go - for work email, simple document viewing/editing (Documents to Go + Thumb Keyboard works well for this), access to our web-based applications, attend WebEx presentations (via Android WebEx client)
5) Online banking - although I could do this from my Droid, the browser and screen size of the Xoom makes this much better
6) Media Management (via Amazon Cloud Player) - manage all of my playlists on my Xoom - because of the Amazon player, they are accessible on all of my other devices
7) Short Attention Span gaming (never had the patience for any game that took too long to learn and play) - my current obsessions: Pool Break Pro (looks GREAT on Xoom), Virtual Table Tennis, Reckless Racing
8) Playing/Learning to play my Guitar - YouTube lessons, Guitar Tuner, Solo (guitar simulator), Ultimate-Guitar Tabs (both web and application)
I used to use my Droid and/or my laptop for most of these - now I just pick up my Xoom. I also intend to use my data plan and the Xoom's wifi hotspot capabilities to replace my $60/mth aircard contract for my laptop for the few times when I need the full power of my laptop outside of regular wifi access.
It seems like every few days I find a new use or another useful app... (about to explore Evernote, for example).
Happy Xooming!