He's perfect! I've nothing against the Rock, in fact, I enjoy his acting; but let's face facts, his current shtick is Action/Comedy. Be Cool, The Rundown, Walking Tall, they were all Action rolls doused with a nice helping of laughs. And what did he do before those rolls? The Scorpion King. Feh.
Vin, sure, he did 'The Pacifier', which I have not seen, and he was the voice of The Giant in 'Iron Giant', but look at The Riddick Trilogy, That's anything but 'action/comedy'. That's hard core kill-ya-with-a-cup action. He spent all of 'Pitch Black' killing aliens!
Sure, there's the problem of Vin-in-DooM-equal-typecasting, but I feel that Vin, fresh out of 'Fast and the Furious' was more type-casted in 'xXx'...or..however you're supposed to type that.
Look, DooM III just came out for X-Box. The PC version of DooM III now has an expansion pack. DooM's been around since the early 90's. I've done what I can to keep the smallish fandom alive, exposed it to who I could, Hell, my still-in-the-smaller-half-of-childhood-years niece has played the original 'Final DooM' on my old PC, lovingly named 'Shitbitch'. DooM has lasted over 10 years, and it's obviously re-surging. Vin Deisel's is the perfect blood spattered, gore-filmed, scowling face to see cresting the handle of a chainsaw that's ripping through a Pinky's jaws! It's his fuckin' genre!
Vin Deisel should play the marine in DooM, it would bring about the jizzing joy of many a fanboy.