I figured I'd just make it a formal topic to echo what everyone is thinking. I kinda doubt that you'll keep TWF working for animal forms, so I'll just go ahead and offer some suggestions on how to do this.
First of all, animal form damage does not scale like weapon damage does. Weapons eventually get additional dice to them, this never happens for wolves or bears. To that end, I propose one of three solutions.
1. The druid gain additional attack die to her animal forms every so often. So Druid level 6 gets +0.5[W], Druid level 12 gets another +0.5[W], Druid 18 gets another +0.5[W], and Druid 20 gets... something worthwhile that doesn't necessarily outweigh multiclassing. Any ideas, guys? Or should the damage bonus be higher? Or... more spread out?
2. Make it so that Natural Fighting increases the Druid's attack die in addition to their doublestrike.
3. Make it so that the weapon equipped can transfer its additional dice to the animal form, like you would normally expect it to.
Furthermore, I also suggest the following changes:
Make the Druid's animal attacks "spontaneous cast" instead of having to prepare them. I sorta understand why you made them spells, but right now they just take up valuable spell slots for no real good reason. It also makes having multiple animal forms pointless, since you can't use wolf skills on a bear, so you have no reason to change into a bear unless you're a bear build. On the other hand, if they are spontaneous casting, that makes things better since now you can switch from a wolf to a bear and back when the need arises, which is the primary advantage of being able to shapeshift in the first place. Considering they aren't even really spells, I think it's fair. An alternative would be to make them bonus feats that cost SP. It's almost the same effect. In fact, that would be better because you can make them no longer affected by anti-magic fields (which doesn't make sense - why would an anti-magic field prevent me from ripping someone's face off and knocking them down with my fangs?)
Also... give us some more area attacks. Something that's close to an equivalent to Cleave and/or Supreme Cleave would be nice. Or change existing attacks into area attacks where it would make sense.