Dominech really has to chose between Henry and Benzema, he opted to go with Henry and a bit of experience is always useful. You cannot pick 2 out of 4 forwards that will end up in the final squad just because of their names, that is just a wrong message to send to french roster, it would not be fair. there are no hope for Benzema to reach top form during this world cup as he has so little playing time. He had to be dropped.
Think about all the others being dropped, Remy, Gomis, Saha (great season!) If he is not good enough to play for the club you play for you are not good enough to play for your country - plain and simple.