There are lots of examples of fantasy stories that center on the exploits of a group of animals. There's The Rats of NIMH, Watership Down, Guardians of Ga'hoole, etc. And I was listening to "Dirty Paws" by Of Monsters and Men and have always thought it sounded like the plot of a fantasy story featuring animals (the birds and woodland creatures in an endless war against the Queen Bee) in the forest of talking trees.

Pathfinder has rules for how the conversion works (there's a spell called Awaken that makes intelligent animals):
http://www.d20pfsrd.com/bestia...er-listings/animals/

I could see this going a couple different ways - first, the animals could be Awakened in a human world, meaning they engage with human things as animals. Or, it could be more along the lines of Watership Down, where the animals are living in an animal world that exists in parallel to the human world (humans and their things being one of the chief dangers in the world). Or, it could be like Guardians of Ga'hoole, where the animals are doing their own thing. I see the Dirty Paws idea going that way.

Would anyone be interested in playing in such a game? And more importantly, who can I get to run it?

I'd play it but i am not the type of man to run a game. I have no ideason how it would work and i am a terrible gm.

I would also be interested in such a game although I don't know a lot of systems so whoever did decide to dm would either need to be okay with that and/or be willing to help learn, or I would just not play. I wouldn't want to mess with other people's experience because of my lack of knowledge.

System wise, there is the old Bunnies and Burrows. I also found a free online system called Great and Small that is designed specifically for animal fantasy. Could use Pathfinder or d20 modern. GURPS or MnM might be interesting. The possibilities for systems are really endless.

As a huge fan of all three of the listed books/series in the OP (especially Guardians, favorite book series as a kid!), I am in great support of this style of game!

I'm not really in a good spot to GM this sort of game right now, but I would totally want to join in to play if it gets off the ground!

I agree with the general consensus that you could really run this with just about anything depending on comfort level and what style you preferred.

... After the Bomb?  Genelab Alpha?

No, not mutated animals. Normal animals (or maybe animals that were given intelligence but otherwise are normal animals).

I'd be interested, I used to keep up with the Warrior Cat series and the idea intregues me

You could also try the Ironclaw series of books.  They were designed for intelligent animals crossed with Fantasy genre.

Following to play