I am gonna be honest, I will be thoroughly surprised if it has mods, I am expecting it to not
so really I can only be surprised here, because I already got the gut feeling and I've come to grips with it over a bowl of cereal.... yeah that's all it took, really.
My dream version is one that's easily modded and can even import plain Doom levels wad-style, and even has a music switch between ambient and raw.
The realistic version I'm expecting is going to be a jolly good romp, but the tools will be released so late into it's life and so convoluted that no one will bother doing anything with them.