I'm sure a few people would like it, but it'd make a few things change. If they overhaul the Shaman class just for that, they'd be making a LARGE change and doing so would take far too much time for something that isn't necessary.
If they changed the 2-handed weapon mechanics, it'd affect pvp warriors and retadins and could make them overpowered in terms of damage.
While people may have their own opinions about it, it's highly doubtful that Blizz would change enhance shamies over to 2-handers, due to the amount of work that'd go into something that isn't needed. If enhance shamies needed a damage buff of sorts, they'd probably stick with DW.