People just can't get his age right, lol.
For the record he turned 28 years old on October 14th, 2011. He will be be 28 years old until approximately Week 6 of the 2012 NFL season. He's old enough as it is, we don't need to short change the man. :)
I did studies of 20+ Pro Bowl QBs throughout NFL history whose starting careers did not begin until their late 20's. Average age of the group was 28 years old, like Weeden himself. The average number of starts was about 8 seasons' worth of games started. These were all QBs that had been to at least one Pro Bowl. The reason I did that? Because you have to remember that the very FIRST reason you're not going to start games in the NFL, is because you're not very good! So even the group I tallied, some of them only made one Pro Bowl and weren't very good generally in their careers, and so you can blame their lack of starts not on a lack of longevity, but on a lack of talent. If you limited it to the players that had been to at least 2 Pro Bowls, then the average number of starts jumped up to about 9 or 10 seasons' worth of starts. Hell, Warren Moon was the same exact age Brandon Weeden will be, when Warren finally got into the NFL...and he ended up playing for 15 years.
One thing I'll say about the above study, the quarterbacks studied included many that played before the NFL became such a powder puff league at the QB position. Now, QBs are protected to an unbelievable extent. And just as importantly, their wide receivers are protected, which allows these QBs to use the middle of the field which is less physically demanding. So you take the above study which shows OBJECTIVELY and in an EVIDENCE-BASED way that Brandon Weeden's career longevity estimate should be about 8 years...and honestly that might need to be bumped up.
But the next big question on everyone's minds is, yeah so he can play 8 years, what good is that if he's still learning for 4 or 5 of those years? The answer to this is to once again, do your homework. Study the learning curves of NFL quarterbacks, especially in the last decade. If you did that, you would notice that yearly passer ratings of quarterbacks that start in their first and second seasons in the pros, are on average IDENTICAL to their career ratings. In other words, by their second seasons, they're already playing about as effectively as they're going to play in their careers. That's not to say they won't keep learning. They will of course keep learning beyond their second year in the pros. But it is to say that IF they are destined to be championship caliber QBs, then they are far more likely than not to be championship viable by their second year in the league, even though they will keep learning. Tom Brady, Dan Marino and Ben Roethlisberger kept learning beyond their second years in the league, they kept growing, but all went to the Super Bowl in their second seasons. Amongst QBs that end up really good, franchise caliber players, half or more end up showing that talent already just in their rookie year.
So you have a career longevity estimate of 8.0 to 9.0 years, and a learning curve estimate of 0.5 to 1.5 years. Again, this is objective, evidence-based stuff. To me you're looking at 6 to 8 quality years out of the guy, as a defensible, objective, evidence-based, expected value.
And so then you ask yourself. Let's say you had a chance to trade for Tom Brady. But here's the caveat: you only get him for 1 year. He's in his prime, he's got no injuries, but he's announced that he'll retire after this year and you have no hope of convincing him otherwise. What would you pay? Say you're a team that is built fairly well and you think you're a QB away from competing for a championship. A 3rd round pick? A 2nd round pick?
Given the 7 year expected estimate for Weeden's career, NET of his expected learning curve, if you wouldn't pay a 2nd-3rd round pick for Brandon, then you're saying you think there is a less than a 1 in 7 chance that Weeden will be as effective in his career as a 34 year old Tom Brady.
And I just don't see that.