As you know, I've already replied in email but wanted to quickly follow-up your comments and thank you for your offer to help us all understand things a bit better in this area.
For the record (again, this was a part of my email to George) I completely agree with the point regarding the timestamping of a photo and the value something like this would bring to us, the end users of such systems as Google Maps and MSN Virtual Earth. But, as you mentioned in your follow-up response, a company would have to commit themselves to a consistent effort to keep the photos updated on a regular basis, something that could amount to a hefty price tag, passing the cost onto the customer base. When both proucts are available to users and developers at no cost (beyond the "advertisement tax") it makes such added bonus as timestamps a luxury I doubt much we will obtain. Bringing advertising revenue into the equation -- A balance between development costs and revenue obviously needs to be struck to make possible the services in the first place. While I couldn't say for sure one way or another, I have my doubts that the potential ad revenue is high enough for such luxuries to find there way into the products. I could be wrong (and hope I am!) but something tells me we won't be seeing timestamped photo's any time soon.
Its too bad. As you point out, with a constantly changing landscape, gaining a feel for when the photo was taken would be helpful in gaining a sense of just how reliable that photo is in its representation of any particular area of the world that it might represent.
None-the-less, your point is well taken and I appreciate the time you took to bring this point to the surface as well as your offer to help bring greater understanding of this process to the rest of us.