Upgrading to 2008 R2

Hi,

looking to Upgrade from SQL 2008 Enterprise to 2008 R2 Enterprise on Windows 2008 R2 Server (64 bit).

Any known issues, gotchas, white papers, etc... that I should be looking for or prepare for?

My guess is that an in-place upgrade should be quite easy as there should not be many changes from 2008 to 2008 R2.

thanks for your help.

Scott