My late game turns are usually around 15 seconds I'd say (sometimes longer if there's a bunch of AI units fighting because then the game cycles around and shows all the conflicts, that's not a processing thing really.) I usually play with 12 Civs (including myself) and 20-24 City States. I upgraded my CPU/RAM/Video Card in late July in anticipation of SC2 and this game, so it's fairly well above system specs.
Anyway, some experiments suggest that workers are the main culprit for time between turns(there's a few threads about how hard-capping the number of workers speeds the game up significantly) so hopefully it's made better. I personally don't have very long load times so it doesn't bother me, but I wouldn't say it's something people haven't been talking about on the forums. It's talked about, just not as much as the AI/Diplomacy/ICS.