It's been well documented that the Steam Controller would get an update and be showed off at Gamescom. The new Beta update to the Steam Client shows the new controller.
It's actually inside of your Steam folder right now, but I'll just shortcut the instructions and show you the picture.
And some of your wishes have been granted: It now has an Analog stick.
A few things:
1) I guess this appeases to everyone? People who wanted one got one, and people who didn't still keep the trackpads. But this still only makes sense to me if they put it out as a way to say "OKAY YOU WANT IT? FINE, THEN COME BACK IN 2 MONTHS WHEN YOU ALL REALIZE WE WERE RIGHT [stomps out of the room]"
2) Looks like they didn't learn from the Xbox and make it convex, although this is a render and not the actual thing. We'll see at Gamescom.
3) LG and RG? What are Valve referring to the paddles in the back as? Grips?
4) Humorously, everything is labeled by letters or appropriate logos except the thumbstick. It's getting the "We let this girl in our circle of friends just so she can do our math homework" treatment.