Will NVIDIA announce GeForce GTX 870 and 880 at Gamescom?

New rumors are showing some interesting developments regarding the upcoming GeForce GTX 870 and 880 from Nvidia. The two Maxwell Gm204 based graphics cards could make an early appearance or announcement mid-August already. There are two events rather soon  where ‘something could be shown to public’. First is SIGGRAPH the second Gamescom. This event takes place in Germany between 13rd and 17th August. 

Now some user at notebook-review forums posted the following:

Check the Title and comment. "New Maxwell cards incoming and then Gamescom. The screenshot shows 3DMark Firestrike in Extreme mode with a 6110 points score, roughly 20% better then a GeForce GTX 780 Ti. 

Now if you blow up things a bit ... you could see an 800 series product mentions.

And then there's this from the NVIDIA UK Facebook. Now obviously we can not validate the score or anything, but this might be too much of a coincidence to suddenly appear on the web.