This would give you what you are looking for. It's not a direct Excel sheet but close enough for me. You have to map changes from 4.0 to 2009 with the first document. You could then map any changes to 2012 with the second document.
This is the 4.0 to 2009 list:
www.microsoft.com/.../details.aspx
This document is not a spreadsheet, but it does include all of the tables with changes. This contains the AX 2009 to 2012 changes, including the tables. :
That will give you all the changes. I've used the new,changed, and deprecated features a lot to solve all sorts of upgrade features. This should get you where you need to go. In my opinion, the second document is the single most important one when it comes to understanding changes in code for Dynamics 2012 as opposed to Dynamics AX 2009.