I'd give such a mod a go if someone made it, but there would be intellectual property issues.
I'm actually planning an original races mod.
As long as the modders aren't making a profit it should be fine. There's plenty of other space games on Steam that have Star Wars and Star Trek mods and there's no issues with copyright. It's a modder making money on copyrighted material without permission that's a problem. Fan mods fan works can always be free with a disclaimer acknowledging the proper owner/company.
If someone make's a Who mod and then charges per download, that's when a big issue and IP lawsuits would start flying.
