I tried Doomsayer in my Control Priest deck, and there was a 100% chance it got countered by Earth Shock or some kind of burst spell. It's amazing how removing GvG has made the game faster than ever. So much that people are starting to run board wipes on turn 2 as the standard just so you can have a fighting chance.
Shaman:
Turn 1: Coin double Troggs.
Turn 2: Totem Golem, Troggs hit face for 4.
Turn 3: Totem Golem, Troggs + Golem hit face for 9 (15 damage total so far).
Turn 4: Spirit Wolves, all face for 16.
Game over, and if you didn't draw a Shadow Word: Pain, Priest is pretty much helpless to this. It has only happened to me twice, but it's enough to recognize that this is a problem. Even if I survived to turn 5 and wiped the board with Excavated Evil, or I pull out Auchenai + CoH on turn 4 to prevent my death, I only have a little health left, and a Lava Burst or Doomhammer will finish the job. Shadow Word: Fear is garbage.
Tempo Mage is the same idea except it's coin Double Mana Wyrm on turn 1 followed by removal spells to buff the Wyrms and clear the board so they can go face. There isn't a damn thing a Priest can do about it (or a Hunter, even). I've only had this happen once, though.
The games are really not faster. The game is slower and board presence is much more important. Favorable trades and letting your board snowball to win the game are very important. There are also far fewer sticky minions. That's why there are more board clears.
The Shaman god draw is no different than other god draws we saw before. We had Mechwarper Mage, Savage Roar token Druids, Tempo mage, Murloc anything, and Face hunter in the past and all of them could easily kill you by turn 4 with the perfect draw.
If you need proof for how much slower the game it's in the proof that so many good decks are running board clears. Using a board clear is a 2 turn play, you clean it and you plan to take it back and stabalize on the next turn. Setting up a 2 turn tactic like this was impossible for everything except the most control driven decks in the game before Standard. Now we see board clears in mid-range and tempo decks.
If you are seeing those kinds of god draw aggro setups and want to continue playing pries, you should include Doomsayer. It offers you a chance to slow down your opponent on turn 2. Even if he silences it, it would stop the Totem Golem and extend his lethal by 2 turns. If it works it not only completely negates your original situation it gives you initiative going into turn 3 against a shaman, which would probably win you the game.
Those god draw situations are frustrating, but you have to look at all of your games and try not to focus on specific situations where you get completely trashed. See my Malkorok example above where he completely fucked me, but he remains in my deck, because even with the occasionally bad outcome he is a great tempo play.