GC has said 5.2 will be looking at the talents to rebalance those that are under used and over used to bring them in line. I think Blood Fear has already been talked about a lot, but what about the others?
Tier 1.
I think this tier is pretty balanced. I still think Harvest Life is a bit of a square peg, but I see plenty of people using it so I don't think it's something that needs looking at this expansion; as much as I'd prefer to see a passive mitigation option on that tier alongside the different healing choices.
Tier 2.
Again, pretty balanced, although Mortal Coil doesn't seem all that popular and could probably benefit from a shorter cooldown.
Tier 3.
Soul Link has issues, I like it, but I don't think double dipping from healing as an upside really off-sets the downside of double dipping from damage from cleaves or multidotting. Could use a buff, either increasing the proportion of health or some kind of safety cut-off so you're not killed when your pet is.
Tier 4.
Blood Fear is the "only" PvP option, and Burning Rush the "only" PvE option. Blood Fear is just too good compared to UW in PvP, when I actually feel UW would otherwise be a pretty good pick. Neither have a place in PvE though, leaving us with BR but that is generally outperformed by Gateway or Teleport leaving the whole tier a little redundant.
Tier 5.
I'll have to break down per spec.
Affliction: Sac is just too strong relative to the other two. Since the buff to KJC, I can't see much use of a pet for the spec under anything but the most extreme circumstances of multidotting where you wont get any MG uptime.
Destruction: For single target encounters, they seem pretty balanced but the synergy Sacrifice has with Havoc and FnB just makes it a no brainer against multiple targets.
Demo: Well balanced, Sac probably a bit weak but I'm not sure it's intended to work overly well with the "pet" spec anyway.
Tier 6.
Since the KJC buff, these are just about perfect. I want all of them at once, which is as it should be.