My favorite young, under the radar guy right now is Billingsley. He was a bit rushed but pitched very well at the end. He's not a rookie though.
If I had to pick one rookie, it would be Lincecum. I also like Havok's choice of Miller as well.
Lincecum has been shut down. He seemed to have run out of gas a bit the last month but finishes his rookie campaign with respectable numbers for someone who had minimal professional experience:
24 GS, 7 W, 146.1 IP, 150/65 K/BB, 4.00 ERA, 1.28 WHIP
He didn't have the W total that Verlander had due to the terrible Giants team but his peripherals were better compared to Verlander's rookie season. Lincecum's season was more in line with Hamels's.
Billingsley looks great right now and still has couple more starts to go:
18 GS, 11 W, 140 IP, 134/57 K/BB, 3.15 ERA, 1.26 WHIP
Especially good since he joined the rotation in July. He might be a bit overrated going into 08 but still, his upside is very high and I wouldn't hesitate to grab him in the middle rounds given his park, division and team. I think he will be just as good if not better than Verlander going forward.
I missed on Adam Miller as he suffered another season lost due to injuries. If I had to choose between Lincecum and Billingsley in 08, I would probably lean towards Billingsley right now. He is probably safer at this point even though his ceiling is a bit lower than Lincecum's.
"Think of how stupid the average person is, and realize half of them are stupider than that." ~George Carlin