Enhancement, except for rets, is the only melee w/o an instant gap closer. And rets have freedom to use together with their sprint. A shaman has his movement speed increases through gw, spiritwalk and uf:fb, but each of these is easily countered with snares and roots. Enh needs some attention mobility-wise, or it will remain easy to kite and the melee with lowest uptime. Need I remind you that we require actual uptime to regenerate mana? Not much using shocks, purging, ue'ing and what not without mana. While a rogue regenerates his recource when not on target, we deplete it with meh methods to close the gap.
As for elemental, except for thunderstorm, which is harder to use than blink or disengage and mostly the only thing they have (frs sharing a cd with ds and es blocks it, so it's down to earthgrab), so easy to counter with a charge/shadowstep/deathgrip etc.
Better mobility is needed, not necessarily through talents, but it would be a good option since each spec can just take what was designed for them.
And instead of "These classes have it so I want it" it's more like "All specs have it, so we're screwed without it".
My suggestion was about freedom effects mainly because wwt already provided that, and us being close design-wise to rets made it more probably imo that we'd get freedom to empower our sprints instead of separate instant gap creaters/closers.
And yeah, I guess talents generally wont be always useful or fun in pve, but that goes for everyone. Remember, blizz basically took all the stuff that before was cooky-cutter and backed it in baseline, and the varying stuff, like Frozen Power, Earthen Power and such, which would vary, was made into talents.
If you look at it like that, pve talents would then be stuff like old shield specialisation, or reverberation or crap like that.
It's hard to make pve talents good w/o making them mandatory.