AFAIK, XNodes are explicitly on the "never going to happen" list.
There will eventually be much better mechanisms to replace them. At the moment XNode-like things are possible from .NET plugins. Eventually there will be native LabVIEW mechanisms. I confidant the NXG solution will be much more elegant then XNodes, as NXG is designed to enable stuff like that.
> AFAIK, XNodes are explicitly on the "never going to happen" list.
There will be no mutation path into NXG for any XNode. As Weibe said, NXG intends to develop its own form of "thing written in G that defines a new node for the diagram" eventually, but that is on the longer-term road map.