Djokovic is too strong there now imo, although there would be no other challengers aside from him and maybe Del Potro.
Fed was nowhere near his 2011 best at RG this year and could still have won at least 2/3 sets. It's a bit like the AO 2012. If Fed played Djok, he'd have shown him the door. Djok got lucky Nadull took out Rog.
Still, Roger is not getting any younger and he just seems to play so much better at Wimbledon nowadays.