Well, I just received my new MBP today and I love every bit of it. Leopard rocks. Except that in the Dock I can't tell if a program is open: what happened to the arrows from Tiger, Panther, etc?
I think the blue dots are a step backwards. Sometimes they look like part of the reflection of an icon. You need more than a quick glance to tell whats open. I prefer the old triangles too.