Michael Affronti blogged in the Microsoft Outlook Team blog about some of the new Outlook 2010 features. I have been using it and it is really fantastic, my top 3 cool features are Thread conversation view, Quick Steps and Account information view!
Check this post at source: http://blogs.msdn.com/outlook/archive/2009/07/20/what-s-up-with-my-inbox-in-outlook-2010.aspx