I support d5 as our reply against 5. Nge2 It just scares me that one of the games won by black was a Petrosian game... Do we really want to be obliged to maintain the same level of defensive play as Petrosian? Cause if we do, I hope someone studied his games quite well...
Most popular responses to 5. Nge2 in the order of the popularity are (bold moves are main lines):
5... d5
5... Re8
5... b6
5... c5
5... b5
5... (somthing novel)