I'm getting more of an idea of what Walter's all about, actually. This trailer seems to loosely define him. He's a very obsessive little fanboy, but he avoids being the fat little George Costanza looking glasses wearing stereotype...Ha didnt notice Link talk the first time i love it... Walters growing on me, but not to much he is a good backgrounder
And yet, his over-optimistic/obsessive nature causes him to act similar to Grover... throwing himself around a lot... that bit where he runs right into the TV sums that up. I like how the character's a lot of physical quality.
That said, I don't see him being a major character beyond the film... a little more minor than Scooter in the old show and movies... I could see him getting a couple web videos. It's hard to tell... there's too dang many Muppets to all get into the spotlight no matter what era it is.