I have it next to me at work but I don't use it for work. I do dev work so unless VS or VMWare can run on the RT, it's pretty much a fun machine. I do see a lot of potential with SkyDrive and Office for folks who live in office to take this thing and go nuts.
Primarily I use mine for a bit of note taking when in meetings - Onenote is perfect for this in either the desktop or Metro form. I Sync these using Skydrive to the Onenote software installed on my main desktop machine at work.
A bit of Word use occasionally, and I've delivered a presentation using PowerPoint (plugged into a projector with the VGA adapter!)
I use mine for Powerpoint presentations, Word and Excel documents, and the Outlook Web app to access my work email. When I first saw that MS was going to bundle a light version of Office with Win8 RT I knew it would be able to replace my work portable (just not my desktop).
Lest I give the wrong impression, I use my Surface mostly for play.
I manage a bunch of contractors on Microsoft's various Redmond campuses, and I take my Surface with me when I'm meeting with clients and contractors. OneNote is great. I use Lync, SharePoint, shared drives via VPN, open and edit Word and Excel files.
I consider it the best of all worlds: a desktop for heavy content creation and game play, and a hybrid device that can be either a laptop or a tablet (for less heavy work and play). This thing fits my needs perfectly.
Do you do anything with PDF docs downloaded and uploaded to SharePoint? Im having some trouble with this on my Surface and if I can't get it fixed I may have to get rid of it - which I don't want to do. I've tried Answer Desk and Micrsoft Chat - at o ne point one of them told me I just can't do what I want but I'm getting a different response from others. Any thoughts?