Yes, I rip Sony's marketing every time it raises its incompetent head above water. Sorry if that's getting boring, but - ooh look - a shiny new "teaser" video on the PlayStation blog...
Did you see anything teased? At all? Anything? Ever? Then, the associated blog post witters on about how you can view the event on your PlayStation... except the Vita. Why not? Its a media device, it plays and streams video. How hard would it be for Sony to knock up a quick app for Gamescom? See here for a few proper Gamescom hints.
If that's the level of attention Sony devotes to the Vita in the warm up to the biggest show in Europe, why would anyone expect anything of interest for the handheld at the actual press event? Of course, I would love to be wrong, but Sony really doesn't give a damn, and proof is written all over that post.
Fortunately Sony marketing isn't responsible for the games at the presentation, or the games themselves. Still, the whole of Sony really needs to be showing a balanced approach and using all the weapons at its disposal, one of which is the small handheld it is too afraid to use. I'm vaguely amazed they showed it in the video.