Two things
1) above posters assuming Google collected the data on purpose. If they did, why would they come out with this now, and why did they only collect 600GB in 30 countries. That's peanuts, and probably consists only of 1 or 2 IP packets per AP. What would they do with that? Nothing.
Google was trying to map AP names to GPS locations to allow yet another way of getting your position (for google maps et al). If THAT rises privacy concerns to you, please do not visit sites like http://wigle.net - wifi spots have already been recorded by many, why can't Google.
2) If Google hands over the data to Germany without analyzing it themselves, they might hand them data from other countries too. They should indeed just delete the data and get on with it. Any further processing or moving around of this unwanted data is plain stupid.
oh, I actually have a third one. For the paranoid idiots above. Get a life.