Yeah, the new maps have been out, nuclear power plant and UN Headquarters. Now, there's one small problem. The maps don't work. And to my knowledge, still don't work. I'll post as soon as I find out that they work.
I want to keep an optimistic view on that, but I agree. With Splinter Cell 4 coming out and all that's involved with it, I doubt Splinter Cell: Chaos Theory's Co-Op maps will be given much priority, but here's to hoping.