I honestly don't think they should make it be able to run on its own... It was made TO mod Fallout 3, why should they waste their time making it so the 2 people on earth dedicated enough to do so can use their tools and engine to make a game that would probably end up svcking?
Why would it svck? The only difference is that instead of playing your game from inside Fallout, you would make an exe and play it on it's own using the same engine. But this is a mod tool so i know they won't bother doing it. The only solution would be to license the Gamebryo Engine...
It was only something i would like to see, since it reminds me of Rpg maker. I was hoping for a 3D version of Rpg Maker, but it's apparently only on Ps2.