Party $20+2: AKs first hand - Do we gamble?

Hey guys. This was my most recent tournament and on the first hand I picked up A [img]/images/graemlins/spade.gif[/img] K [img]/images/graemlins/spade.gif[/img] in the SB. About 6 (maybe even 7) people limped so lets say there was ~120 chips in the pot when the action got to me.
I raised it to 200 total and the BB immediately went all in for his 800. Folded around to me and I called getting about 2:1 odds. He showed KK and no ace came so he won.

The question I ask is, do we call this 100% of the time? This was the first hand of the tournament so I clearly had no read on my opponent but I tried to narrow his hand range down to an estimation:

AA or KK about 40% of the time
22-QQ about 25 % of the time
AK about 25 % of the time
Any other two about 10% of the time

Are these estimations about accurate? I mean, at this level I have seen people put their whole stack in preflop on the first hand with KJo and even worse. Especially in this type of situation, where there is a lot of dead money in the pot, do people decide to become the madd bluffer.

Any advice is greatly appreciated.