Polymorph:  I didn't mean polymorph.  Specifically I meant the chaotic aspects of the barbarian's rage which, though not technically linked to lycanthropy, have parallels: the temporary increase to strength and durability, speed, etc.  That's what I meant.  It's not RAW either, but it is a thematic consideration.  Is the lycanthropy being used as an affliction?  Then it's a curse, evil, and shouldn't be a boon (good phrase there, btw).
Werebear:  I don't count the other lycanthropy types.  Ever since I can remember (2e, I think started it) there have been the evil werewolves and the happy-clappy were-goodguys-because-nature-is-awesome.  My original group saw the DMs girlfriend become a were-dragon.  If there was a were-puppy template I'm sure someone would love it for their gnome or familiar.  Natural lycanthropes could be a race, sure, and I don't mind that.  I just wouldn't mix them with the demon taint of the wolfman, that's all.
Personally, I'm just a fan of afflicted lycanthropes.  I don't see goodly creatures transforming people's alignments through an affliction like werebearism to be a realistically "good" thing.  Evil is corruption, so I can see that; and it works with the curse/affliction aspect of lycanthropy.
In theory, a werebear Paladin would want to afflict as many orcs, goblins, and evil humanoids and human criminals with werebearism as they can.  A band of werebear clerics could seriously upset the balance of good and evil, needing TN druids to step in.  Make sense?