The Kernel 3.13 mailing list announcement is – as usual – not very detailed, and in any case only shows changes since the last ‘release candidate’ (-rc8): http://firstname.lastname@example.org/msg572887.html
For a much more detailed look at new features, etc., there is a very useful summary here:
And.. More specific architecture/driver change information, here:
Robert Gadsdon. January 20, 2013.