Well, personally I like other races very much, especially dwarfs. But I also think that, as companions or allies, it would bring too much Tolkien-feeling, like someone said above. Dark elves, schemer dwarfs as enemies would fit better in the world of BB. But of course there could (or should?) be exceptional cases like the rare possibility to get one of those races as a companion through a random event or a special quest or something like that. So it would be something very special.
