Those are really good choices for animals. I hope we can get more than four (or five with an exhibit) animals for Europe. Western Europe may have lots of large cities, but that doesn't mean Europe is devoid of wildlife. Hopefully we'll get more animals than usual. Besides the flamingo, Europe doesn't have a single animal (I think the generic timber wolf was confirmed somewhere as being American).North America I would speculate this (somewhat influenced by my wishlist for NA):
American Alligator
Cougar
Moose
Raccoon
Exhibit species could be anything but love to see : San Francisco garter snake
Building Pieces: Wild West mixed with Native American scenery items
Europe same approach (somewhat influenced by my wishlist for NA)
Badger/Wolverine/Red Fox (can't pick)
Alpine Ibex
Saiga Antelope/Red deer
Iberian or Eurasian Lynx
Exhibit species could be anything but love to see: European yellow-tailed scorpion
Building pieces; I think this is where Europe DLC will shine - a lot of great architecture styles to pick from.
Personally think that one of the Eastern Europe styles will even help the people who are asking for "basic building pieces".
And I really hope we get the North American ones too. Especially gators. They may not be as big as salties or other crocodiles, but they can still be dangerous. A raccoon would be a great choice. They could easily reuse the red panda rig and a lot of its animations for a racoon.
I aslo wonder what will happen when they've gotten NA and Europe. Maybe they could start doing sequels to existing packs, with creatures people wanted. They could probably do two for Australia, emu, wombats, wallabies, grey kangaroos, quolls, gonna, freshwater crocs, and a plethora of exhibit animals could still be added.