It's one of THOSE postsFollow

Dual wield is generally the way to go from what I have seen/read. I was 2-hand in PVE until having enough talent points for dual wield and let me tell you, getting that random string of bad luck and getting 2 misses in a row with a slow weapon is no fun at all.

With that said, the main reason enhance spec goes into the resto tree is to take Nature's Guidance for the 3% to hit with melee attacks, and to increase the range on your totems.

In your enhance tree, even if you were going to use a 2-hander, why wouldn't you take stormstrike?! It's your bread and butter. Finally, toughness is just a bad way to spend 5 talent points. Soloing your armor shouldn't matter too much as long as you are wearing mail, and if you are taking hits in an instance something has gone wrong in the first place.

Other than that, your trees look pretty good. I used something like this until I went resto: http://www.worldofwarcraft.com/info/classes/shaman/talents.html?0000000000000000000050250021050213353115150005301000000000000
The 2 points in Guardian Totems is just there to fill in. They can go anywhere you like really, just don't spend them in Shield Spec :) I took it for the reduced earthbind cooldown for pvp is all. There are 2 unspent points, use them where you like. I think I put mine in healing focus just so I could heal a little easier while soloing with something in my face.

Points of contention on Enhancement:

Lightning Shield is pretty pathetic in both PvP and PvE, even talented, and the improvement from the talent is "meh" at best. Furthermore, if you're going to be more than 5 points into Enhancement, you always want to take Guardian Totems to reduce Grounding Totem's cooldown.

Enhancing Totems is purely a PvE skill and hard to miss either way. By all means, keep it for PvE, but if you need to move some points around, this is the first place you can afford to lose them.

Imp. Weapon Totems is, again, more gravy in raids, but won't be missed in PvP or PvE. Points are tight, I would skip this one. Your party members won't know the difference and they're bloody lucky that you're even giving them WF in the first place.

Shamanistic Rage really only works in PvE right now since it's immediately and effortlessly dispelled. If you plan to raid, take it. Otherwise, take Nature's Swiftness for PvP.

Now, on to your Resto selections:

As an Enhancement Shaman you'll never be healing except in PvP or maybe some extremely rare, panicked off-healing. Either way, you're likely never to cast Healing Wave and will be reaching for Lesser Healing Wave 99% of the time. Get Tidal Focus instead, every little bit of mana counts.

Imp. Reincarnation is pretty worthless IMO, even in PvE. Some people swear by it, whereas I can count the times I've "barely" missed Reincarnation's cooldown on one hand. If you're noticing that this talent is making a difference, your party/raid is probably chain-wiping and you've got bigger problems than the choice between a 40 or 60 minute self-rez. Pick it up if you're really looking to maximize raid utility, otherwise skip it. Either way, another talent useless in PvP and you want those points for the next tier.

You'll need Nature's Guidance if you're raiding; for any other purpose (namely PvP) the % to hit is overkill.

If you're PvP'ing, Healing Focus is a must. You will quite literally never get a heal off outside of Nature's Swiftness without it.