"Wolverine + Superman = _?_"
(What else would you expect?)
As much as I like Wolverine, I think it's pretty safe to safe that Superman would put the beat down on the "guy who's the best at what he does". A healing factor and some metal (yes even though it's adamantium) is no match for the grocery list of powers that Superman has (super strength, super speed, flight, x-ray vision, heat vision, invulnerability, super breath, etc... Even if we concede that Superman can't break adamantium, I'm pretty sure he could bend it - good luck putting those claws away Bub.