Just received my copy of Office 2010 Beta in the mail today.
First impressions are good, not much has changed between 2007 and 2010, although there is a nice feature in that there is a file button where the Office logo was on 2007. This means moving users from 2003 to 2010 might be a bit easier.
Outlook 2010 has the biggest change so far regarding look (https://cdn.geekzone.co.nz/imagessubs/d935e7d8ccdba47ae7e62d926ec870b6.jpg)
I am still trying out the features at the moment, so if anyone wants me to try something out let me know. I will be hopefully installing it on my work PC tomorrow to try it out in an enterprise environment.