Just a quick note that I've been polishing the layers feature and even without the layers dialog it's becoming rather usable. So basic layers (of a sort) might actually make it in for this release.
Here are some of the relevent changes:
* I've retired the inkscape:groupmode attribute as it has served its purpose
* You get Sodipodi-style "enter group"/"leave group" commands on the context (right click) menu which can be used to switch to using a group as a layer, or switch back to that group's parent
* when a group is in this "layer" mode, the drawing tools create shapes within it and you can drag and select its objects directly
Here are the items that are still needed:
* The "group mode" setting needs to be per-NRArena key, and persist across hide/show cycles (currently, the change in event handling behavior is global, even though layer activation is per-SPDesktop)
* Some sort of visual indicator of the current layer would be nice. I have provided an SPDesktop (SigC++) signal for this purpose, which can be connected to via SPDesktop::connectCurrentLayerChanged()
* should e.g. "Select All" etc be influenced by the current group?
-mental