You're definetely going in the right direction.
To answer your question about Icy Talons, yes. Especially if you plan on focusing on heroics and 10 mans. My guild does not run with an Enhancement shaman at all so it isn't even a question for me.
Killing Machine is taking up alot of your points and I am strongly against wasting points in it.
Morbidity is not needed but it does help if you're having trouble with AoE tanking. I personally don't have it right now. Epidemic is an absolute must as it allows you to get some extra attacks in before having to refresh. In an AoE situation refreshing is as simple as tab Pestilence but on bosses that obviously isn't an option. I did notice that you don't have Icy Reach. If you're relying on HB as your AoE attack then you need to have it. More range allows for more error.
My sig has my armory link. Check out the spec. The only change I would suggest making would be to take out the 2 points in 2H spec and 3 points in Subversion and to put them in Bladed Armor to buff yor HB. Not sure what kind of weapon you're using but HB should perform better than OB for you.