There is an interesting graph on the Google Open Source blog showing the breakdown of this year's students by their country of origin. Even though the graph does not list countries with student participation below certain limit, it provides enough information to draw some interesting conclusions.
At the first sight, it looks like the US(191) and India(182) are miles ahead the other countries when it comes to the number of participating GSoC students. But when we take a second look and add the few European countries that do show up individually in the graph, namely Germany, Poland, Romania and France, we see that just these few EU countries combined are on par with the US. The final EU number will be probably much higher than that if we add students from the remaining 23 members (for instance, at least 2 for the Czech Republic).
Clearly, there is some great programming potential hiding in Europe. Now, if only Europe knew how to make use of it.