putting artboard XAML on separate window / screen
Simple question, but is there any way of putting the artboard designer on one screen, and the XAML on another in Blend 4?
It's a real pain constantly flicking between the two when I've got three monitors to play with!
Short answer, no.
What you can do however though that I do often is set your Designer & Code View to be side-by-side via View -> Split View Orientation -> Split Views Horizontally then drag the Blend window across two of the screens with the split obviously between the two screens. That works pretty well.
Otherwise you could have the design open in Blend in one screen, and the xaml open in VS on another screen...becomes a pain though since whenever you save on one, you'll be prompted to update on the other.
Wish there was a better way, but I'm pretty sure none exist besides those mentioned. Hope this helps.