The first official GOES-15 Sounder visible image (above) became available starting at 17:30 UTC on 08 April 2010. For more details on the first GOES-15 Imager instrument visible images, see the CIMSS Satellite blog, the SSEC Spotlight, and the NOAA News pages. GOES-15 (GOES-P) is the final spacecraft in the GOES N/O/P series.
The GOES-15 will go through its post launch science test during the Summer of 2010 — the first IR images from the GOES-15 sounder are expected in late April of 2010.
Sounder images and products from the other GOES satellites can be found at the CIMSS GOES Realtime Derived Products site.