My original intention was to work SUO into an EUO replacement. I found that I could write a pretty nice and usable interface and editor, but I didn't have the technical knowledge to tackle the client interface portion completely. I had a working engine that worked much like EUO originally did (when it didn't have any packet communication), so I could see the character attributes, world position (even unencrypted passwords kept in memory). The packet stuff stumped me however. Finally, my time in UO started to wane and my drive to complete the project diminished.
But SUO did turn into a really nice editor; whenever I do any script modifications I HAVE to use it. (since it's basically tailored to MY ideal development system)