Do you have any sort of metagame you are preparing for?
General improvements I'd suggest would be adding some lands, getting rid of Mondronen Shaman Flip as well as Plummet , Naturalize , Abundant Growth , Blasphemous Act and perhaps Instigator Gang Flip and Reckless Waif Flip
Adding more lands (going to 23 or 24) makes most sense if you keep having quite a few 4cmc creatures in the deck
Your mana doesn't seem quite shaky enough to need Abundant Growth , but if you don't like how it is right now, perhaps a few lands that tap for more colors (Copperline Gorge and since you're running a lot of Humans Cavern of Souls ) might help fix anything you need the Growth for now.
Blasphemous Act doesn't seem to be quite what you want to be doing if your plan is to play creatures and attack your opponent, you might want to run Bonfire of the Damned if you want to kill a bunch of your opponent's creatures, that, and Revenge of the Hunted does much of the same, sometimes.
Instigator Gang Flip seems sweet, but 4 mana is a lot, and it's effect is rather small if it enters the battlefield with few or no other creatures down, I've personally ended up cutting it from all my werewolf decks. A bit of the same with Reckless Waif Flip , she seems great when you get her down turn 1 on the play, but after that, she gets bad pretty quickly
August 18, 2012 7:35 p.m.
Now, I've already suggested a few cards to go in, but there are a few others that you might want to include in the deck
Garruk Relentless Flip , between making an endless stream of tokens, killing a creature, searching up a creature you need, and giving all your creatures +X/+X, you ought to find a use for this guy, besides, if you come up against a control deck, planeswalkers are generally good.
Wolfir Silverheart , 12 power and toughness for 5 mana, and you get 4 of that to attack with right away, and you only have to have one other creature for it to do that, as opposed to Instigator Gang Flip 's four
Daybreak Ranger Flip helps deal with flyers, in particular the always annoying Delver of Secrets Flip which hovers around in every format, and the flipside just kills things, and killing things is good, it helps you not die
Ulvenwald Tracker , while not a werewolf, also kills things, particularly because your things are often bigger than your opponent's things, and that sometimes leaves your opponent without the ability to play creatures, and then you win
And last but by no means least, you might want to add some amount of Pillar of Flame , Galvanic Blast , Shock , Incinerate , Arc Trail , Searing Spear , or Brimstone Volley , since killing your opponents things is a good way to not lose, and not losing is a good way to win