Not enough genetic material from the dodo exists to stand a chance of bringing it back. We may get close to a mammoth, but there is still a lot of genetic gaps that need to be filled in, and then what? Probably exist in zoos? Animals that we eradicated and can resurrect I think we should if possible, but for the most part we just don't have the entire genome, and then there would be no diversity in the population.

It's going to take much longer than people think to bring these things back, and dinosaurs never will. There just isn't enough DNA. Now if you could invent a real pet cemetery, now that would be cool! Just don't build it next to my house!