Anyone think it would have been cool to show Captain America picking up Thor's hammer? Maybe during the battle Thor gets knocked for a loop, Cap's shield is lost somewhere, and he reaches for the nearest weapon available. Just until Thor is back on his feet.
Not a "sword in the stone" moment or a "hero wields ultimate weapon" moment, just a quick look of surprise by Thor that confirms what we already know: He's worthy.
Or maybe Mjolnir lands at Cap's feet and he just tosses it back to Thor, ala 390.
My idea is that during a fight, Thor gets knocked down and separated from Mjolnir. Then after the fight's over, we get a close-up of Mjolnir just as someone lifts it off of the ground. Thor gets to his feet, looking surprised, and then we cut to Cap walking over and handing Mjolnir back to Thor, then walking off without even really realizing what he'd just done. Sort of a "Cap is worthy of the hammer, but it belongs with Thor" moment.