I can see this being used to bring back delicious species, such as the Beluga and the dodo.
This is actually an interesting proposition: what will the meat and animal products industry look like if science is able to freely and cheaply clone all sorts of species, including extinct ones? Will dodo cutlet become the new filet mignon if they can be grown?
This goes hand-in-hand with the thread on "printing body parts" and "printing bacon", where lab-grown cells are rapidly combined into tissue. Proper scientific endeavors will be a great boon for agriculture, as there will be less restrictions on land usage and fewer ethical problems with lab-grown meat.
You know how birds are said to be some of the closest descendants to dinosaurs? Well I remember seeing a program on the Science Channel or something that explored this. One thing they did was take a chicken egg and they changed the DNA so that certain "switches" where either flipped on or off so as to achieve the result they wanted. As the embryo grew it was observed to be behaving as predicted in that it grew a longer tail, teeth like structures on the beak, and other traits that made it look very dinosaur like. They ended up destroying it before it was close to hatching. I've always wondered what would happen if such a creature was allowed to grow until it hatched... We need to use a ostrich egg next time though.
"Cloning dinosaurs" will probably turn out a lot like the Jurassic Park novel: Wu notes to Hammond that they're not REALLY cloning dinosaurs, but rather making new monsters that have never existed in nature that just seem like dinosaurs. While actually bringing a dinosaur back to life is extremely difficult, creating a custom species that greatly resembles dinosaurs is much easier.