The first of these releases (named 2.0dev1) is ready. The application has been ported to Unicode, and the latest version of the rich edit control is used. The file format is changed. The existing format .gde files can be read, of course; the newly saved files will be in the new format. Changing the foreground and background color of a node in the tree pane is now supported (via the context menu only as of now). The node colors are also used during print, preview and export as well. The search dialog is resizable.
The files are available on sourceforge as winguide-2.0dev1.
If you have some time to spare, do have a look! The best way is to just get the binaries zip file, unpack it somewhere and run the guide.exe from there.
Update [26-Jun 14:17 GMT]: The files on sourceforge were somehow corrupt, I've updated them. Thanks for the tip from an anonymous user!