The one thing I loved about Windows Live Mail was the blatant simplicity of the whole thing. With Outlook, I struggled with the Ribbon being in the message composition view and clogging up my desktop real estate unnecessarily. However now, the Ribbon can be easily managed to hide, display or disappear entirely. Either way, you still have easy access to it if you need it.
To read more on Office 2010 Beta 2, head over to the iGeneration blog.