AK gets 4 bet preflop; worth an all in postflop?

[Self Made]

Bodog History for Hand #987583783
Hold'em No Limit ($0.25/$0.50) - 2007-11-16 23:56:49
Table 'Waldo Stadium' 9-max Seat #3 is the button
Seat 1: tecknic7 ($32.25)
Seat 2: Hi5 ($49.75)
Seat 3: Villain ($51.05) (button; stats: 31/13)
Seat 4: brgerflipr ($51.25)
Seat 5: Hero ($52.55) (big blind)
Seat 6: TheRaven34 ($55.70)
Seat 7: jerken27 ($92.80)
Seat 8: PPSTU ($59.50)
Seat 9: latko35 ($38.50)
------------------------------
NEW HAND
brgerflipr: posts the small blind $0.25
Hero: posts the big blind $0.50
--- DEALING POCKETS
Hero is dealt [Ks,Ac]
TheRaven34: folds
jerken27: calls $0.50
PPSTU: folds
latko35: folds
tecknic7: folds
Hi5: calls $0.50
Villain: raises $1.80 to $2.30
brgerflipr: folds
Hero: raises $4.70 to $7.00
jerken27: folds
Hi5: folds
Villain: raises $4.70 to $11.70
Hero: calls $4.70
--- DEALING FLOP [Qd,Kc,8c]
Hero: checks
Villain: checks
--- DEALING TURN [2c]
Hero: bets $15.00
Villain: goes all in $39.35
Hero: calls $24.35
--- DEALING RIVER [7h]

Sorry about the format. If anyone knows of a working Bodog hand converter, let me know.

Villain raises a lot preflop (only have 61 hands on him though). When I get raised on the turn I have the nut flush draw. What do you think he has? How would you have played it, and why?