A few things you should note about yesterday's Xcode beta release...
First, new sizes and naming updates apply to asset catalogs. Here's my latest list of what I believe you need to be building on a per-app basis for icons. No, none of this is documented anywhere. I also believe there were no changes to launch images.
Second, pay special care to the beta API diffs -- especially anyone doing view controller layout. I just spent 4 hours updating a common pattern throughout several books of sample code.
Finally, is it just me, or is that the ugliest Xcode update ever?