Hello Frederick,
AFAIK, Amazon doesn't let you use your own cert, so it's fine if you don't mind the long cloudfront URL for your pictures, but is a problem for people wanting to use their own domains.
By waste of resources, I meant that if it's only used for the login page, for some admins, it would save on bandwidth costs if assets were loaded locally. Granted, it's only a fraction of the bandwidth, but every little helps ;).
So the behaviour of "HTTP only" has changed in the dev version? In the latest stable version it would simply load pictures from the CDN using http instead of https and that would create "mixed content" errors in browsers.