After going through the codex a couple of times, there were a few things that I noticed about the psychic powers available for the Blood Angels. For one, they're really good - I would say on par with the Space Wolves in terms of effectiveness. It's not surprising that the last three Marine books have strong psychic potential and Librarians being very cost effective options.
Let's go down the list really quickly and see what the Blood Angels have..
Smite - Same as C:SM. 12" S4 AP2 Assault 4.
Might of Heroes - Gives you +D3 attacks.
Wings of Sanguinius - Redbull gives you wings. Not really, but you get Jump Pack movement.
Unleash Rage - You and your squad gains the Preferred Enemy USR this turn.
Blood Boil - Pick an enemy unit from 12". It takes a wound with no armor save. If you roll 5 or less on your psychic test, you choose the model.
Blood Lance - 4D6" straight line that ignores friendly models. Enemy units touched by the line takes a S8 AP1 Lance hit.
Shield of Sanguinius - All friendly units with 6" of you get a 5+ cover save.
Fear of the Darkness - 24" Enemy unit takes a morale test at -2 to their Ld.
Shackle Soul - Enemy needs a leadership test to do anything; move, shoot, run, assault.
The Sanguine Sword - Your Librarian has S10 this turn.
So now that's out of the way, let's talk about what really stands out. In my previous article with Space Wolves, I talked about Murderous Hurricane, Living Lightning and Jaws of the World Wolf being big players. In this new Blood Angels Codex, I can see Sanguine Sword, Unleash Rage and Blood Lance/Fear of Darkness being the winners. Of course if you're a Librarian Furioso, the Wings of Sanguinius will be top priority (that and probably Might of Ancients or Blood Lance). Nobody wants to fight a AV13 Dreadnought with WS6.. let alone one that can fly.
So let's look at Sanguine Sword first and how this psychic ability changes the metagame. This power makes your Librarian S10 with his Force Weapon. In case you didn't know, Force Weapons also ignore armor saves.. and S10 is double the toughness of all the major players in today's metagame: Thunderwolf Cavalry, Nob Bikerz, Tyranid Warriors, almost all the ICs and SCs in the entire game, Plague Marines, you name it. How many of those actually have invulnerable saves? Almost none. That means on the charge, you have the potential to send many of them to their doom. Your S10 cares not for multiple-wound models because they immediately die with each wound inflicted. You don't even care if you get into combat with a Trygon or a Wraithlord because you'll know for a fact you can now put wounds on it. Keep in mind that Mephiston has this ability as well and he can cast three psychic powers a turn! He can definitely wound anything in the game and detonate his soul at the same time. You can even walk up to a Land Raider and go to town. S10 with no armor saves simply means this in the world of 40K: Nothing is safe from you. Good day sir.
Next we'll talk about Unleash Rage. You give your squad Preferred Enemy, thus allowing them to re-roll all hits in combat. Here's another reason why you don't need a Chaplain.. not only can you confer this ability to them the first round of combat, but for every combat afterwards. Hmm.. this makes that slightly more expensive Reclusiarch option even less appealing. Note that Mephiston also has this ability, but since he's not an IC he can only use it on himself.
After looking at the codex today and realizing that the ability does not effect models but indeed units, I think the third place position might be tied with Blood Lance and Fear of Darkness. For Blood Lance especially, it seems like JotWW has started a trend with the whole connect-the-dots abilities. You roll 4D6", add them up and draw a line from your Librarian. The average roll is 14" so it's pretty short ranged. Any enemy unit it touches takes a S8 AP1 Lance hit. What does this mean again? If you get a flank shot with it from your Librarian Dreadnought into a cluster of Chimeras or Rhinos, good things will happen. Not to mention the Lance effect and AP1 means you can possibly take down a Land Raider as well. Similarly, you can use this ability with a Librarian with a Jump Pack so he can pack that critical punch on a target that he otherwise can't touch. Pretty good at the end of the day.
Next we have Fear of the Darkness. This ability allows you to target any unit within 24" and force them to make a morale check at -2. If they fail, they run away like little girls. This ability obviously does not work against walkers, vehicles or fearless units, but it does have its uses. Morale checks are something that is a real pisser if you fail. You immediately flee to your table edge and you're essentially out of the game until you regroup (they can still shoot though). I can see this ability as something that will flush out heavy weapon emplacements or any unit with a leadership of 8 or so. Most squads these days are either fearless, leadership 10 because of the IC that's with them, or Ld. 9 because they have a sergeant. I must say though.. the fact that you can fear someone off the board because they deployed too close to the edge is always funny (for you).