Version 5 has just come out. You can go under the sea, and the waves seem to be animated, at least in some areas. (I went to the Marianas Trench, of course. But only for a short while, because one thing that this makes clear is how frikkin’ big the ocean is.)
There’s an overlay with current clouds and weather (but that may have been available for a while).
There’s historical imagery: one of the buttons opens a slider with years marked, and you can go back in time! Wanna see what San Francisco looked like in 1946? It would be interesting to get that model of Imperial Rome hooked in here somehow.
Another button lets you change the time of day and watch the sunlight spill over the mountains.
This was announced in a BBC story I noticed while reading the stories on the recent snow in England.