Good QBs still take time to develop. Check Eli Manning, 4 years before it clicked. Brady you could easily say at least 2 (his arm strength was blah in those years too). I think teams that throw young qbs in have the right system in place or an over the top QB talent. Big Ben was all about system in his first (Superbowl) year. Flacco and Ryan might be the over the top but they also have very solid offensive lines and talent around them.
The game has changed and I think you see many teams players in the first year learn on the job more (whether this is because of FA or better more pro scheems in college ball, or a combo each)
Trent is doing well, if he stays healthy I except he will continue to do so. A 400 yard game with this talent around him would go a long way towards his getting to be a true star in the league.
BTW Rex Ryan is doing a good job with Sanchez and they are going to cause us some problems this year.