Google has just pushed out a significant imagery update for Google Earth, although the precise scope of it is not yet know. According to the Google Earth Blog, updated countries include: China, USA, Africa, Bahamas, Italy and many others. It seems to be quite a large update.
If you think you’ve found some updated imagery, compare the Google Earth imagery to Google Maps, as Maps is still showing the old data. It’s a great way to know for sure if imagery in a particular area is fresh or not.
If you find any new imagery, leave a comment on the GEB post and they’ll get it listed.