A reader begs to differ with this analysis:
You’ll probably hear from more folks than me, but I don’t think the batter would be considered "hit by pitch" under MLB Rule 6.08(b), because it is unlikely that the batter would have made an attempt to avoid being touched by the ball. That is a prerequisite for the batter being entitled to first base without liability to be put out. Also, it is likely that with his x-ray vision, Superman would pitch a strike, and so even if the batter made an attempt to avoid being touched by the ball, the batter would not be entitled to first base.
Another goes there:
And the Chicago Cubs still couldn't win a series with this guy …
George Plimpton explored this topic in a famous April Fool’s Day spoof for Sports Illustrated in 1985. Thankfully, SI posts old stories in their entirety. If you notice, the first letter of each word in the subtitle gives away the joke – but many many people were fooled when this story first ran. And it’s a fantastic read.
I'm sure others have pointed you to the classic Larry Niven essay, "Man of Steel, Woman of Kleenex" which takes a similar analytical approach to the issues regarding Superman and Lois Lane having sex. If you haven't read it it can be found here.