My friends, a QBs development is not usually a steady upwards slope and frequently there are going to be peaks and valleys. However since Baltimore he has thrown 6 Tuddys and 1 interception. He has shown steady improvement and he is getting better not just with his throws and decision making but his pocket movement and his protection and route adjustments. The Brett Hundley we saw today was much better than the Brett Hundley we saw against Minnesota and thats in inclement weather with heavy gusting winds. IMHO his development has likely been curtailed by MM's conservatism. For instance it took a game of him getting knocked around against Baltimore before he learned to start stepping up in the pocket, and today he showed signs of moving in the pocket while keeping his headup. For a quarterback to learn you have to let him play a little and IMHO MM doesnt do him a lot of favors with running into 9 man fronts on first and second down before throwing into coverage on 3rd and 8+.
Take it easy and relax, he is improving like most quarterbacks do from playing and yes he does have a lot of plus attributes and a lot of the you can't teach that traits, I like how he bounces back from bad plays bad games and how he doesnt try to force the issue when things aren't going his way. I also like that the kid is a real load when he does run the ball. I would even think about getting him some packages even when Rodgers returns. Maybe let him come in and do some read option in those rare games when Rodgers is just off.
Things to work on:
1) Throwing early, wont just result in more open receivers but it will help the next issue.
2) Footwork, part of it is that he likes to try and extend the play but he doesnt have the arm talent to throw while falling down like Rodgers. Brett throws a pretty good ball though when his feet are on the ground, but he throws too frequently while falling backwards or off to the side. Get it out earlier brett when technique wont be a hindrance.
3) Pre-snap, knowing the coverages and making decisions... he is getting better with this though. He also needs to figure out ahead of time when he needs to throw fast and when running might be an option.