"At the end of the day, Arby is a pretty prolific poster proposing a plurality of proper posts for us."
- big_adventure
The key points being
1. Mjolnir travels the Path Thor desires it to follow back to his hand, even if Thor isn't actively directing it (Since it doesn't fly through any buildings while returning to Thor in Dark World, actively turning in order to avoid them)
2. Mjolnir can accelerate to high speed under it's own power.
So if Thor desires, he can toss it at Superman, and then recall it to his hand via a path that goes through Superman
Technically all Mjolnir's got to do is leave his hand, and getting into a fight while hammer's doesn't stop the recall. Even if Supes starts beating the crap out of him, He can probably tough it out long enough for the hammer to hit him
(Assuming that "Enter orbit in seconds" speeds are enough to tag Superman, of course)
Or assuming that Supes would get taken out by one hit from Mjolnir.
To be honest, it seems like you're grasping at straws here for Thor to have even a bit of chance against not being blitz-stomped. We've never seen Thor activate this speed up on his own in combat situations, especially not while getting blitzed to holy hell, and even if he could do that it's far from certain that it'll take out or even hit Superman to begin with.
I kinda am grasping at straws, mostly for the challenge of it.
Now, for more potential arguments for Thor, he was able to keep up with The Hulk in a fight, who is in turn faster than the Abomination, who was fast enough to turn around and smack a rocket out of the air before he hit him.
So while he's not as Fast as Supes, he's probably fast enough to at least take someone sort of Action before Supes crosses the distance.
It the Mjolnir tossing Tactic doesn't work, then another viable option might be to grab hold of Supes and someone a bifrost to him, BFRing them both.