At bbs.keyhole.com there is a forum where photo updates are announced

http://tinyurl.com/eg5p3

On October 3rd, we updated Google Maps and Google Earth with the
following new imagery:

- Cross Plains, Texas
- the whole state of Minnesota, South Carolina, North Dakota, Missouri
(updated to 2005), Idaho, Maryland, and now full coverage for the
entire state of Texas
- Updates to Florida (most of the state covered now)
- 15 high-resolution cities in Germany
- update for London, 2006 data at 10cm
- South Georgia Island (courtesy of the British Antarctic Survey)
- Albany, OR; Lubbock, TX; Port Townsend, WA; Portage County, OH;
Trumball County, OH
- 32 Digital Globe high-resolution cities (updates and new coverage)

In addition there was a significant update to the regular Digital Globe
imagery all over the world.

Enjoy!

Also there is a thread started 3rd Oct headed, "why have you downgraded
the images of London?" with quite a few messages.

http://tinyurl.com/hsdod