This is absolutely unacceptable. That's like you having to submit your personal details to Microsoft in order to just run a program on Windows. Absolutely nuts and it will not go as they think it will.
Starts with scary warnings for unsigned apps (with a workaround), then they start imposing extra restrictions for unsigned apps, and then they make the SmartScreen workaround more difficult to enable (maybe it needs a registry edit), then they'll remove that workaround in certain markets/editions (maybe the Home version first). Finally they'll remove it everywhere.
imagine microsoft having the moral high ground for once