Personally, I think it's a GREAT idea, as long as you have the time, patience, and money to do so. It can be anywhere from amazingly easy to quite a bit of work taking in a stray. If it was someone's pet before it may adapt quickly. I'm not sure of the number of communicable diseases that a cat may have they could be passed to a rabbit or dog, but with other cats it is a large consideration, with FIV & feline leukemia being the two big risks, but I don't think either of those can be spread to other non-felines. I would quarantine the new kitty until you can get a vet check up, blood tests and necessary vaccines. In another room, garage, etc... This will also give the cat a place to feel secure while it gets used to the other animals.
Just some things to think about. It can take some patience sometimes, but I think it's a good thing as long as you are prepared.
