It looks like that feature is going to be pretty limited in Germany. From the article:
"Google is working closely with a German government privacy agency, ensuring that its imagery meets the country’s data privacy regulations. Among them is a requirement to delete older images, which means that you won’t be able to use Street View to travel as far back in time in Germany as in other countries once the new imagery is live."
That kind of data should definitely preserved for future generations - national libraries and archives could be trustworthy guardians of such data that is only meant to be accessed again with some time delay.
Or we encrypt it very well, throw away the key, and wait for computation to catch up :)
"Google is working closely with a German government privacy agency, ensuring that its imagery meets the country’s data privacy regulations. Among them is a requirement to delete older images, which means that you won’t be able to use Street View to travel as far back in time in Germany as in other countries once the new imagery is live."