This question has been around ever since the movie Jurassic Park wherein scientists extract DNA from mosquitoes trapped in amber. This type of technique has its roots in the belief that mosquitoes from the time of the dinosaurs contain the DNA extracted from dinosaurs and preserved in tree resin or amber. This kind of thinking is very optimistic as it suggests that we are able to find pure and preserved DNA that could be lurking anywhere in the entire world and that we have unlimited resources in our attempts to recreate extinct Jurassic, Triassic or even Cretaceous creatures not just dinosaurs. Of course, if we are able to actually find and confirm the dinosaur DNA, there is no guarantee that it will be perfect.
When we say the word dinosaur, what comes to mind are the prehistoric leviathans and the gargantuan beings before the time of evolved mammals, but, when we say cloning, what comes to mind would be exact replicas of the organism about to be cloned. Any DNA that can be found inside a mosquito would probably be contaminated with the mosquito's own DNA, thus rendering the DNA useless, unless of course, scientists would like to perform the tedious and exhausting work of mapping the entire sequence of mosquito DNA (which took years for human ones) then, separate the DNA of the mosquito from the DNA of the dinosaur. This kind of separation is currently a technical impossibility and will require years of research and development into cloning and DNA mapping techniques.
After all that, let us just say that, we managed to separate the dinosaur DNA from the mosquito's, then what? For starters, the dinosaur DNA might have gaps, missing strands of DNA information that are lost to the world. This DNA would then have to be replaced, with other reptilian creature DNA (or bird DNA as suggested by some scientists that raptors evolved into modern day birds). These creatures would then be more like hybrids of dinosaurs rather than the real deal, they would then go on to display some of the characteristics of modern day reptiles rather than the original qualities shown by the prehistoric leviathans.
Fine, let us also say that the DNA found was pure and uncontaminated. By reaching this far in the game, this type of DNA would be incredibly rare and worth a lot of money. To create a real life, living, breathing dinosaur they would have to find a way of breeding the dinosaur as the male and female gamete is not available for in vitro fertilization. What we would have to do would be to use the cloning method, which is very unsure as the chances of anything coming out of such an experiment that is to say the number of cells that survive the cloning process is maybe one in a hundred.
Thus, after all that is said in the above I think that cloning dinosaurs is a possibility but, is not going to happen anytime soon as the chances are of creating a pure dinosaur (not a hybrid mind you) is a million to one after factoring in all those factors stated above. Besides, let's face it what reason would we want to create the Jurassic Park incident in real life?