Well I can't say that Felton will ever be Nash. But with that said I believe that Nash did not help Amar'e as much as people thought. Even without Felton he can be effective and has proven he does not need a dance partner to be effective.
Feltons however is just a completely different player so the comparison is a little moot. Felton is a more physical rugged guard then Nash is. Felton plays decent defense, gets a few steals and is very difficult to exploit in the post. In that respect you can already say Felton is a far more complete player to begin with.
Offensively is another story, Nash's passing ability is also matched by his ability to get a shot whenever he wants and his superior range. Coupled together you have to make a choice stay home with cutters and spot up shooters or let Nash go off. Felton is similar in this regard but not quite as gifted offensively, he will get better tho.
In terms of Leadership and Toughness they are tied. Nash manged to still play with one eye an Felton played a double overtime game with a stomach virus both were effective.
While many would laugh at this comparison now, nobody is laughing at the argument that Felton is in the early running for the All-Star Game or that he is our second best player. Right now its still a little early to really make an argument either way tho.