I just arrived home today after spending 5 nights at the Pop Century. I requested building 6 which is the 70's, and it was beautifully refurbished. It's the building behind the Mickey phone. The room was spotless and mousekeeping kept it that way. The beds seemed more comfy too!
I didn't see or hear any remodeling work going on while I was there so I have no idea which building or decade that they are working on at the moment.