If you look at the bottom left hand corner of a Street View image you can now view the month and year when the picture was taken.
Another nice little feature I’ve noticed Google Maps testing recently is the highlighting of search results. For a while now when you search for a location in Google it has shown a map with the searched area highlighted. Google have been testing this feature in Google Maps as well.
Finally, in Chrome (but not in Firefox and IE for me) the satellite button in Google Maps now shows the satellite view directly beneath the button.