Good point. Google will be challenged to handle these issues, and certainly can't be so direct about it. But if removing them draws visitors to the smaller search engines, Google will need to respond in some fashion.
Kudos to Google for this. It's the exact opposite approach to security than that used with Explorer. Instead of closed code and trying to hide flaws, they open the code and offer rewards to those who find them. In the long run, this will lead to better and more secure code.