I've noticed a thing that is missing, either intentionally or otherwise. There is only the very scantest of bestiaries in the Core. The other books add a few more, and there is the errata download with some critters in it on this very site (for those who have internet access and know how to get here). Are the stats for animals roughly unchanged from previous versions and will that do until a new book comes out?
Rules for making any animal you want will be in the Bjornaer chapter of HoH: Mystery Cults. Until then, the web bestiary and past supplements can be used to fill in the gaps.
The numbers for combat statistics don't seem to have changed a whole lot. Does anyone think that there's a problem with using the 4th ed. bestiary more or less as is?
A creation system for animals is about the best thing I can imagine. One of my characters is a shapeshifter of dubious Faerie origin who can become some rather odd animals, all of which are native to Portugal. These include a raven, a vulture, a genet (a small, predatory cat similar to a civet cat), a barracuda, and a common adder. Having a way to make these animals up in a balanced way is somewhat critical to playing her as a character.
The only trick to that is finding it. As a mostly-noob, I'm thinking of problems that will be encountered with groups new to the game who won't know to look and who won't want to pick up an older edition book that will be replaced by a new one. It was the one seriously missing thing, aside from crossbows (that was weird). And now that David has let out that beasties will be found in Bjornaer, it's all gravy.