Nole looks very strong now. It's not as if young talent is really looming. Tsonga/Berdych etc already proved they can't keep up with the big dogs. Fed may be on the way out (very slowly though). I don't believe Nadal will come back strong. Murray and to a lesser extent Fed might be his only serious opponents for some years to come in which case he can string together another 6+ slams.
This. Very well put. In two years time Fedal won't be an issue anymore. Who's going to challenge Novak then?