The "textures" we commonly refer to are the textures used to texture the 14 levels of the original game. In this mod you will probably hear about 3 different textures:
Original Textures: These are the original ones from Dark Forces and are of a very poor resolution and quality, as you can imagine.
Re-processed Textures: These are the original textures but run through several filters to make them look better - and are also a higher res.
Re-created Textures: These are new textures created from scratch by our texture artists. These are very high res and often come with shader scripts when light is emitted from the texture. Basically, they're of the standard present in JKII.
Currently, we have re-created (I think) all the textures from Secret Base, and several other levels are in progress. For work in progress levels we are using the re-processed textures to give us an idea of what the final product will look like.
I hope this clears things up. Perhaps I should add this to the FAQ