In the video, the comment about "be able to get stuff done, get paid and move on" sums it up for me.
WPF just doesn't solve any problems my company or our customers have. I think that's why so many people want to stay with XP - it's not as slick but it does the job and there is no obvious benefit in upgrading.
Where I've had a need for some custom component on my forms, I've managed to write something (if it's relatively easy) or buy an existing component. My preference is to always buy something over building from scratch or to reuse something someone else has
If I was to write a new product from scratch, I would consider WPF but I suspect I'd stick with the tried-and-true WinForms.