There was a scan of an article from the 4/5/06 Motorcycle News (UK) where a top BMW exec announced 2 new "F800" bikes, including the F800GS. It included a photo, but I can't find that post any more.
Here's what Raptors & Rockets thinks it will look like, and IIRC they were not too far off:
Here's a quote: In an interview that was conducted by Motorcycle News UK this week, Dr. Herbert Diess, the Director of BMW Motorrad GMBH, made the following comment about the upcoming additions to the F800 series:
"2006 is the year of the 800cc bike - we will be concentrating heavily on this segment"
"Currently we have the F800s and ST, but we will also be building an enduro version, like the GS, and a naked bike."
Looks like some pretty stiff (terminal?) competition for the F650, and will even be competitive to the R12GS bikes for the "inseam impaired".
Should be lots of fun...