Disclaimer - I don't really follow football all that closely, although I do enjoy keeping tabs on the Broncos and truly do want them to do well (it's the Colorado way). However, I'm a big Avs fan, and I can't help but notice a that the Broncos now seem to be an eerily familiar situation.
This summer, the Avs got two new goalies - one young guy (Varlamov) that could be the next big thing and a former playoff MVP coming off a major injury (Giguere). Varlamov is extremely athletic and can steal games away, but many of his techniques still need a lot of work. Giguere is exactly the opposite - his strength is his ability to read the game and make exactly the right move at the right time. They've been playing together for 6 months now, and Varlamov has already started combining the techniques he's learned from Giguere with his natural abilities. Because he's constantly learning from someone that is really strong in the areas he struggles in, Varly's figuring out how to fix his weaknesses and has already become a much better player.
From what I've been able to tell, this is somewhat similar to the Tebow/Manning debate. Yes, the two of them play different styles, but that's exactly why Manning can be a great mentor to Tebow. If Tebow's passing game is lacking, why wouldn't you give him a year or two at least to learn under one of the best passers in the league? Yes, taking away the starting position may seem like a slap in the face, but he now has the opportunity to learn from someone who can really help him improve his game. Even though he may be a "backup" for a few years, there is a very good chance that he'll become a much better player if he stays in that situation than if he got the starting gig somewhere else.
Maybe I'm missing something, but why does it have to be Manning OR Tebow? Tebow's 24 and still has a lot left to learn. Yes, he's good now, but he could be even better in a few years with Manning's help. The Tebow fans may holler for the team to start him or question the long term plan, but having Manning around for a few years probably is the best long-term plan for Tebow. Heck, if nothing else, keep Tebow for a year or two and let him work on his game, THEN trade him when his value is high. Dumping him now doesn't benefit him or the team and just ends up leaving a bad taste in everyone's mouth.
Yes, there will be fan drama involved in keeping both, but I really think that having Manning and Tebow going into next year is the best thing for the Broncos. When Tim Tebow is your backup, you know that even if Manning runs into injury troubles, you're going to be okay. Plus it solidifies the QB question for both the present (Manning) and the future (Tebow), which should come as a comfort given the big question marks at that position since Elway left.
But then again, I'm far from an expert on the subject. Perhaps I'm oversimplifying the issue. But from an outside and unbiased perspective, I really don't see a downside to keeping both quarterbacks.