Re: should Chapman, Leake, Wood pitch out of the pen in 2010?
Off the top of my head, recent successful young pitchers who have not served time in long relief:
Lincecum, Cain, F. Hernandez, Cole Hamels, Verlander, Porcello, Billingsley, Kershaw, Jurrjens. And probably others, if I spent some time musing over it.
I think the Twins broke J. Santana in via long relief, and that obviously turned out much better than Liriano did.
I just don't know that there is a "best" way.