Still way more than most. I think Lin is an interesting case of a player who might be a borderline NBA player talent-wise, but when he got his opportunity, he found himself in a perfect situation, in the right system, and has so far made the absolute most of it and has played out of his mind. This is probably the best he's shot the ball in his life, or up there at least. He's in an offensive system that really caters to his strengths. And the injury to Carmelo and the absence of Amare are two things that probably helped him shine immensely where he's been forced to be aggressive in looking to score. Just a really great situation for him to take advantage of, and he has taken full advantage of it.
And as for NBA scouts and GMs, the job of predicting how a player will translate to the NBA and how he will improve and develop certainly isn't a perfect science. There are intangibles Lin has shown that you can't measure. You can't always see or predict work ethic, desire to win, basketball IQ, not always anyway. Same thing happened with Ben Wallace, but it took the right situation and a real opportunity for him to find his niche in the NBA. Probably can say the same thing about Bruce Bowen or guys like Wes Matthews and Reggie Williams.
Just goes to show you, when you do get that one chance, that one opportunity, make the most of it.