I'll let the actual pvpers answer, but I think this right here is the wrong question to ask right out the gate. I don't think you can decrease that gap much as both just have different inherent makeup in how the powersets with those ATs (not to mention the ATs themselves) function.
Plus there are inherent things to being "melee" and being "ranged" in this game that can't be overly overlooked. Holds or stuns for instance could help Melee close the gap, but since holds don't actually hold in pvp as of i13, there you go. Also Melee has armor, Ranged doesn't usually, or at least not as much as Melee, unless they build for it. (Though with defense not actually being defense in pvp . . .)
Plus anything you do might not be looked upon favorable by either side of that divide. Also the devs did try to make things easier and more simplified based on how they felt they could "get more folks to pvp". And we know how that turned out.
There are so many variations in this game of what it means to be a "melee" and "ranged" that I'd be wary of any suggestion that starts with trying to answer "how do you close the gap between melee and ranged DPS", but willing to hear any wild ideas.