Developer portal article with high level descriptions of the new 8.1 features and links to more details
A breakdown by category of the new APIs for 8.1
Word doc on how to re-target your 8 apps for 8.1 and some of the “quirks” that you might find
Build video that covers migration to 8.1 and shows some examples
Build video on how the new Search features work
Build video how the new app size features work (versus Snap state)
Build video on how the submission process works for 8.1
(please add your own links in comments)!