You'd think that DC would have researched the popularity of Clark / Diana before committing to this relationship.

Somehow I doubt it. A quick tag search on Archive of Our Own shows that there are still only 19 stories for this ship, compared to 44 for Bruce / Diana, 404 for Clark / Lois, 665 for Clark / Bruce and a staggering 5617 for Clark / Lex.

laater - clearly Smallville has a LOT to answer for...

They should have read this panel first.

That's just - just so wrong.

If you read the comments of that artwork you'll see that the POV with regards to Wonder Woman that they've taken. That stupid, idiotic Niven essay has gummed up things for too long and now it's affected the New52. I wish someone would write an essay (probably a nurse or doctor) that would refute so many of the assertions in the old, old outdated commentary that is so often quoed as a reason Lois "isn't enough." It's also times like this that I abhor the shared universe setup that DC has decided to embrace.

Doesn't Thor in Marvel have relations with human females? Wouldn't he have potentially the same problems Superman does, yet nobody even blinks at this "god" falling in love with human woman? (Sorry, I just rewatched "Thor" recently.)

I suspect (and I could be wrong) but the reason they don't blink twice has to do with "gods" being a magical being and therefore can do just about anything they want. Superman is more "sciencey" (in a pseudo-fashion) and therefore vulnerable to "scientific" assumptions. Although the fact that Clark/Superman is not a god is kinda being re-written in the DCnU.