FIX (via http://registry.gimp.org/), which worked for me:
I've learned that some particular fonts are constantly in use or 'locked' by the Adobe Acrobat Update Service.
Try stopping or 'killing' the Adobe Acrobat process (via Administrative Tools Services; or simply using Task Manager - right-click on the Adobe Acrobat Update Service, and select 'End task').
This should release any locked fonts and allow the GIMP loading-up process to finally succeed with loading the fonts database.
Note: Not necessary to stop the Adobe Acrobat service everytime you run GIMP, only just for the intial post-install run, when (or if) it hangs. Apparently, once Gimp's internal fonts-database has been created, it seems to run OK thereafter, even when the Adobe Acrobat service is up and running in the background.