Ummm, what? If the Dolphins take him with the 8th pick, I wouldn't call it their entire future.
The Dolphins have a serviceable QB right now in Matt Moore. If they take Tannehill, sure its one pick, but they will give him the keys right away and let him go whether he's ready or not. If he is then congrats you got your QB, if he's not they will work with him for 3-4 years before admitting it and moving on. Either way, if you take him you're leveraging quite a bit on him being "the guy". If he's not then you just wasted the last 4-5 years and have to start. Sure it's not their "entire future" but I think you know what I mean.
It's one pick, and no one is trading their whole draft to move up and get him at #3.
I disagree. I think somebody will trade up and take him. Just like Jax traded up for Gabbert last year and the Vikes traded up for Ponder. With the new CBA its not as big a risk financially to do so and I think QB needy teams are going to go mad trying to find their guy.