Klein is nowhere near where he needs to be to become an effective passer in the NFL. Tim Tebow with better mechanics, so in that regard Klein is a nice developmental prospect.
Klein doesn't have a great feel for diagnosing coverages or going through progressions from the few games I've seen him play.
IMO whoever takes Klein should take an 'old school' approach towards his development; let him carry a clipboard for 3-4 years, run the scout team offense and in a few years see what you've got.
Cam Newton was an anomaly, you don't see guys go to the most competitive conference in the country and dominate running and throwing the football in only one season.
RGIII had thrown over 1100 passes in college games and was much more refined than most draftniks had originally thought.
Collin Klein still isn't much of a threat as a passer, but with his tools and athleticism he could surprise down the road and pay off big for an NFL team with a long view towards developing him.