In Thor Volume 1 Issue 390, Steve Rogers who at the time was going by the Captain lifted, Thor’s hammer, Mjolnir. With the upcoming Avengers movie in May I was thinking, what would everyone think to Cap wielding Mjolnir?
I'm sure there are going to be several opportunites with various members of the Avengers attempting to lift the hammer. Having the Hulk attempt to lift the hammer would be pretty funny, Hulk gets riled up about not being about to lift Mjolnir and then Thor comes along, picks it up and knocks the crap out of Hulk.
Back to the subject at hand, personally I would not be against it as long as it is something quick and nothing more than Cap giving Thor his hammer back during a battle not even realizing what he just did.