@uberhulk: You said "she slit his throat with her tiara...." as though that were something to scoff at, and unless I missed a match, she hasn't 'slit his throat via her tiara' in the New-52. Pre-New 52 Wonder-Woman was the one pictured, and being discussed(best I'm aware), not New-52 or Kingdom Come.
Three different versions(of Superman), two of which have no bearing on the one addressed.
@lowlaville: No she slit his throat with her tiara. Her tiara is magic (at least it was pre crisis). Superman has poor defence against magic so that doesn't really mean anything.
I wish people would stop spreading this nonsense.
His defense isn't "poor", nor is he "weak" against magic. He just doesn't have any particular resilience to it(beyond what someone/anyone on his level would have,and he in fact has the odd couple showings of resisting transmutation from a magical-being, and withstanding a magical attack which took out the rest of The Justice League).
In other words: Superman is affected just the same as anyone else in his tier that's exhibited iffy or lacking durability against magic.
Which would be most/nearly all of the people in his tier-bracket.