As far as the taskbar features go, Windows 8 explorer actually supports multi monitor setups intelligently (and behavior is somewhat configurable) so there is probably no need for third party explorer modding programs anymore! Although I haven't tried setting wallpapers per monitor yet, which is technically supported out of the box in 7 but is a nightmare to use (you must select a picture for each monitor in one open dialog box. I have thousands of pictures, and typing the file name to quickly get at one unselects anything you might have had selected).
Speaking for myself, I have three monitors and a TV attached to my desktop computer. I value minimalism and efficiency (I see the irony here
): my emerge stuff is all in the central monitor and positioned exactly like I have it on my laptops. I don't really like to frequently move between the monitors in casual use. I very rarely interact with emergetasks, it's more of a visual indicator of things I have minimized so they're not lost (I miss MiniMize
), I personally wouldn't really use it per monitor, since I like having the two secondary monitors empty but for the wallpaper when not in use.
I use the secondary monitors for things that slowly update and don't demand my constant attention (IRC, winamp, various progress bars of copys/installs etc), but when something changes I do notice it in the corner of my eye.... as opposed to having it buried under everything else and forgetting about it.
I'll also use the secondary monitors to play videos I don't really need to look at, I can just listen to while working or playing (TED talks, daily show, etc). If I want to watch something with my full attention, it goes on the TV.
Then there are times when I really need to multitask: VIM in the central monitor, documentation of various things on the left and VIM tutorial on the right ( XD ).
Anyway, it sounds like what you're talking about is what 8 does: you can set it to only show on the taskbar the programs that are currently on that specific screen. If we're lucky, 8's SDK will have something related to the management of windows and which monitors they're on to make this easier to implement.