I think after the spring game it is clear that Tuggle is most certainly the third string QB, although there is an article in the Mercury today where they interviewed JT (too early to start calling him that?) and he says he feels that he is going to really turn it on this summer. Seems like he still thinks he has what it takes to move up to starter, so the competition could still be there.
I'm a huge Klein fan, so my opinion may be a little biased, but I think Collin has the position on lock. His passing has improved most certainly in the distance and accuracy areas. His performance at the spring game was about as good as you can ask for. Add that to the fact that he is very familiar with the playbook and Synder, and that he is excellent with both teammates and the press, least we forget what he can do on his feet, I'm very comfortable with him taking over at the helm on offense.