I'd say it certainly has aesthetic value. WHo amongst us wouldn't love to see a mammoth or a dodo in a zoo? For that matter, if the great apes go extinct over the course of the next century, I think it could only be a good thing that we could still see the populations living in zoos.
It must have academic value as well. Even if a cloned animal in an unnatural habitat couldn't tell us much about the behaviour of the extinct species, there must still be all manner of studies scientists could do of their morphology and biochemistry, which they wouldn't be able to do with fossils and a DnA sample or two.
And it definitely has economic value, too - provided the extinct animal is cute/impressive/popular.
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