Nobody gave delpo any chance 2009 final and Fed look really amazing against Djokovic in semi final. Rafa looked really good against Delpo in semi final and nobody give Anderson any chance. For me there are many similarities.
I think the difference is that Del Potro was 20 years old, he had shown great promise already that year, and he still had plenty of magic to discover. Anderson is 31, and is unlikely to offer up much new at this stage? Would make sense to compare it more to Wawrinka's late blooming break through than Del Potro's.