The Playing the Percentage page in the February 2007 issue of Poker Pro Magazine caught my eye.

The page shows the odds that someone has a better hand then you preflop in a 9-handed game.

Check out the odds:
KK: 22-1
AK: 22-1
QQ: 10.5-1
JJ: 7-1
TT: 5-1
AQ: 5-1
99: 4-1
KQ: 3-1
AJ: 2.5-1
KJ: 2-1
AT: 1.7-1
QJ: 1.5-1
KT: 1.5-1
[February 2007 Poker Pro Magazine page 59]
It makes sense that KK and AK are the same. When you have KK there are still 4 aces in the deck so AA can still be dealt 6 ways. When you have AK there are only 3 kings and 3 aces left so KK and AA can only be made 3 ways each for a total of 6 combinations.