Kosteniuk is an attacking player, so she doesn't want the boring ending after 3...dxe4.
1. e2e4  1... c7c6  2. g1f3  2... d7d5  3. d2d3 I must say that this is a rather curious system to employ against the Caro-Kann Defense. Followers of this solid variation are usually happy exchanging queens with a safe position.