I wouldn't count anything out. The Xbox "exclusive" DLC eventually came out on PS3 so you never know. Maybe this stuff could end up on the consoles. Its not like Valve is PC only. They do have some stuff on both xbox and ps3. Right now I could see it going either way.
That being said I still pre ordered for PC. Although I don't know if I will spend as much time playing the PC version as I have on ps3. I still think it will be cool to have since I play more PC than anything else usually.
The Nemesis Mode for RE:ORC remains a Xbox exclusive today.