It's surely a possibility. We are relatively strong in the nature of coding, textures, particles, gui, etc. Luckily most of our maps use zero Doom 3 textures/models but we do have a small collection of made particles using doom 3 textures as the source(stuff like some fire, smoke, etc). Most immediate that we can think of are replacements for all /common materials, lingering guis that doom 3 had hardcoded, and many base scripts/defs that we've inherited from fairly commonly. Sharing info would surely be of benefit between us when it comes out.