I love this mod. Of course, I don't run XF in a live environment at the moment but I can see how useful this mod is.
The thing that really sticks in my throat is static sidebars - I am just not a fan. I feel that static, never changing sidebar layouts become just as invisible as static advert positions.
What would REALLY make this mod exciting, at least for me and lots of others, is the ability to define 'per widget', which nodes they appear on, or not appear on. This will allow a forum section or other node to carry relevant content [widgets] for that specific section and not be tied into reusing a sidebar generically site wide. This would seem a natural add-on progression.
Hope this idea makes it into the addon at some stage, it will be needed at some stage by more and more people. This is already possible in vB4's everywhere sidebar mod.
To be even more flexible, and to go one step further than the vB mod already mentioned, you could allow a widget's visibility based on usergroup also.
Anyway, as someone who doesn't even run XF on a live site feel free to take or leave my suggestions as you see fit. Either way, cracking mod - well done xfrocks!