It will. The main changes are going to be in height and depth (because of the top and front panels). There's a few changes of the S810 that I think are great:
The top was tooled to allow for radiators with funky fan spacing. The top radiator now sits further back in the chassis which allows for better airflow to the front most part of the radiator (360 radiator). The bottom supports 240 and 280 radiators natively now, and there's a large fan filter below to make sure your rad stays dust free. There's a lot to the new girl in town.