Saw there are several threads already to discuss it (in fact, too many redundant threads, especially 'notable api changes' vs 'api changes'), but none of those threads have any full diffs of all types of changes. Here are diffs for that.
Function diffs (includes exposed FrameXML functions, too lazy to filter those out):
https://www.diffchecker.com/oxjtkczh
Enum diffs:
https://www.diffchecker.com/azaeqj87
Event diffs:
https://www.diffchecker.com/t3g9mktx
Widget diffs:
https://www.diffchecker.com/il1di4ac
Console Variable diffs (thanks Nodus Cursorius and Semlar):
https://www.diffchecker.com/8n7nkotk
Download link (personally I think the diffchecker links are fine, but just in case somebody wants the files used to make those pages):
http://www.mediafire.com/download/81...6v21691API.zip