Well, if it's like any of the various animals (dogs, cat, sheep, cows) that they have cloned then it will be an exact clone of the animal they're using as a source. It won't be gestating inside another mammoth, of course, and so it won't be birthed by it's mother but it will be a mammoth. As to whether it will live long or not, I don't see why it couldn't.
There is some comic relief in the Genetics community when it comes to Russian Genetics. Hope they actually succeed though.
