We first considered this possibility a little over two years ago, and it’s finally here — historical Street View imagery!
Activating it is quite simple. While viewing imagery in Street View, simply click the clock in the upper-left part of the screen (as shown in the image above) to choose a different time. Note that this feature is rolling out in stages, and you may not yet have access to it.
The imagery dates back to 2007 in some areas, and could be quite useful in a number of scenarios, particularly as the collection continues to grow over time. This feature is not yet available in Google Earth (only on Google Maps), but presumably will be added at some point in the future. However, Google Earth does have the incredibly useful historical imagery feature. Having both of those available in one interface will be quite nice!
You can read more about this new feature over on the Google Lat Long Blog.