OK, I'm relieved that canon Clark does have his powers and that (hopefully) Nightfall will be dealt with. But what happens after that?

Alt-Clark definitely has to go and meet Martha and Jonathan. Must happen.

And it would probably be wise for Alt-Clark and Superman to be seen together quite a few times in the next few days. If possible.

I really feel for alt-Clark, not only knowing intellectually what his doppelganger has, but now knowing it from experience. If he has to go back to his lonely existence, that will be very tough.