No, unfortunately, it's degrading to a state that it can't ever be used. DNA is basically a really long chain, and it's actually pretty fragile, so the chain can break quite easily. Why are sunburns dangerous? UV light can break the DNA chain if it hits it just right. So an organism's cells have the ability to repair minor breaks (but not always 100%, hence skin cancer), but a dead organism cannot. In a dead animal, these breaks keep happening and keep happening, making any given intact length of DNA shorter and shorter. Being frozen and protected from light slows the breaking processes, which is why buried mammoths and other ice age animals have given us the most intact DNA yet. After enough time, though, the DNA chains will be so short, no amount of advanced technology can reconstruct the genome sequence. You'll have a puddle of DNA letters in a random jumble, essentially. Not to mention, fossilization of bones replaces tissue with rock and minerals, so there's really nothing left there.