Acutally, no; at least not over all of it (I'll probably get one or two). I'm thinking of doing a laminate floor down there but that will be later (when I get a job again). You actually don't want carpet on the floor since it sucks up high frequencies. It's usually better to have a reflective surface (throw rugs aren't so bad since you can remove them to keep the room "live").
I did finally put a mic up this morning just to see how it's sounding so far and I was quite pleased. I still need to figure out how I'm going to build diffusors for my back wall, then I'll be "done". Now I just have to hook everything back up again and start doing some recordings.