In 1998, Grant Morrison, Mark Waid, Mark Millar, and Tom Peyer submitted a proposal for Superman 2000. The Superman of the 21st century, if you will. The idea was to work up from the Post-Crisis framework to the gigantic scale of the classic Silver Age. I kept thinking back to it while reading this.
One of the things they wanted to do was undo Lois and Clark's marriage. A Brainiac-Luthor team-up would cause Lois's memory of Superman's identity to kill her, and he would convince Mr. Mxyzptlk to save her, but he does so by undoing the marriage. (This was later used in Spider Man) Presumably, this is being referenced when Luthor says Superman's lucky the former spared his marriage.
Superman explaining his new power set also comes from that, as their kick-off was to have been that one day, after absorbing yellow sunlight for 29 years, Superman wakes up with full Silver Age power-levels.
I absolutely hated the way Luthor is written here. All the reason he needs is "Superman is now a threat to every living thing." Try living with that, you muscle-bound ogre! Spewing nonsense like 'a lovesick tween' is out of character and, in my opinion, doesn't belong in any villain. I hate when they write the Joker like that, too.
Didn't care much for the art. Superman looks really weird in some panels, and Lex looks ridiculous.
How come every other superhero already knew about it, that they could protect themselves and the Kents?
What I want to know is: Do the writers believe in the 'classical' approach to characters, against recent changes, or are they mocking fans like that, like what Superboy Prime became used for.