Comparing the interface between versions is a quick way of highlighting the changes between Excel 2013 (preview) and Excel 2010.
Home Tab
Insert Tab
Page Layout Tab
Formulas Tab
Data Tab
NOTE: in Excel 2010 the Analysis Pack has been added but in 2013 it has not.
Review Tab
View Tab
Developer Tab
Backstage View
(Note: white out is to protect my privacy, in this screen shot and not a feature of either version of Excel)
Sara Fennah's Blog 
So, since excel 2013 is out now. are there any major changes compared to the preview version/excel 2010? Interface looks pretty much the same, but its hard to judge since the screenshots are a little small. I found a guide with bigger ones for excel 2010 (http://www.excel-aid.com/the-new-excel-2010-interface-structure.html ), but none so far for 2013. Anyone here who can provide that, or just give a short opinion whether there are huge changes or not?
The changes are not huge but there are a couple of new features – Flash Fill and Recommended Charts/Tables/Pivot Tables being the main ones. I do have a QRG for 2013, but haven’t yet converted it to a blog post. If you email me at info@fennah.co.uk, I can send you a copy for personal use.