Whilst this is awesome, it's going to piss off a hell of a lot of web hosts.
IPv4 addresses are already a commodity, and it's getting to the point where even big hosts are having trouble getting enough justification for larger IP pools. With dedicated SSL certificates, every domain's going to be needing it's own IP address.
I played with this a few weeks ago and after I made sure every URL is protocol agnostic in preparation for such a switch I constantly ran into outside content/scripts to break the SSL. We rely on adsense/DFP/Other networks banner ads for revenue. Lots of those campaigns and lots of ad agencies we deal with are not ready for SSL.
I aborted the switchover for that reason. Will wait a few more month and attempt again. But if my google ranking could get improved I may look at this sooner then later.
In addition SSL is the foundation for SPDY and SPDY does make sites faster. Safari will soon support it as the last major browser.
You don't need to set any redirect changing from http to https... you simply force https and that is enough. http to https is actually not a domain change, as http is not considered part of your domain name structure. http / https / ftp / so forth, are web protocols.