As John Nack has told us in his blog, the Photoshop-UI is going to have a facelift — the design of the upcoming CS4-applications will feature a prominent “application frame”: a window containing both interface elements and documents. Take a look at John’s screenshot to get a feeling of the new UI-concept. This goes mainly to Windows-users because the applications will have their “own” window-style that includes interface elements like it works on a Mac.
So you will be able to have multiple document layouts to adjust your workflow. You may move the entire application including its contents from one monitor to another easily.
John also mentioned in his article that there will follow some other nice features like tabbed windows and a split-screen-view.
I think Adobe is going to introduce great improvements to their upcoming Creative Suite applications because the user will have much more possibilities to adjust his workflow. The personal likings of the users get more important and so the whole applications become more fluid and customizable.