Regarding the Viewer since there are a lot of questions about it.
It will be skinnable. Right now the entire background is a pre-rendered image that could change, but as-is it isn't necessary. I asked frosty to make his images in 1 to 1 scale and he was nice enough to comply. What this means is making a rendering of your own personal layout is as easy as dragging the pre-rendered controls over top of your blueprint you used for cutting out the controls and then putting a nice cpo underneath in photoshop or your favorite image editing program. The labels can be moved around and have different fonts and colors and such. They are very modular and have multiple "special functions" such as the title and control type shown in the image. (Excuse the spelling I sent that preview pic at 3 am)
The viewer supports various command line options including sending a lof file (the skin file that it uses) and sending the screen position. This means that yes multiple layouts will be supported and yes it will work on dual monitors because you can simply make the position after or before the edge of the primary monitor. And the viewer auto scales itself if you pass a size option so no worries.
Although it won't be included in the first beta I intend to allow lof files to be loaded in a hierarchy, similar to the way ctrlr files do. I also intend to expand the heirarchies to include control types. What this means is a crafty person with multiple control panels could rig it so that the right skin is autoloaded depending upon what controls the games use.
Also I will add a hwnd command line argument that'll give focus back to the hwnd you call after the viewer loads. In other words you can place it anywhere in the fe's skin as an element and treat it just like a standard png file, even though it isn't. Of course the fton ends will have to be recoded to support this, but it should be worth it.
I hope that answers any questions, if there are more feel free to ask.