It is clear that Google's acquisition of DoubleClick will introduce a major change in the online advertising ecosystem. Much ink has been spilled questioning whether the combined operation will have a beneficial or negative effect on ad agencies, ad networks and other online advertising players. These are all valid questions, but they're unanswerable at this point. What's clear, however, is that Google's attempts to expand its role in this ecosystem will not go unchallenged, and that if Google isn't careful, its grand plan to marry search and display advertising may well hit the rocks.