Uninformed ramblings.

It could be solely because I missed both of these presentations and their discussions (PAC 10 tournament for the win), but I don't think Nietzsche and Tolstoy are talking about the same thing at all.

Nietzsche discusses the two tendencies of order (Apollo) and disorder (Dionysus). He talks about how the introduction of chaos into order (the collapse of the principium individuationis) both terrifies and delights man, and how art can only really result from the clash between these two tendencies. However, Nietzsche seems to refer to these tendencies as being contained within each individual man--they are individual experiences.

Tolstoy's theory of art revolves around shared emotion. He says that art can only result from the infection of one man's emotion to another man.

These two ideas are not the same at all. Nietzsche is talking about something which is felt at an individual level, though the feelings are similar across all mankind. Tolstoy, on the other hand, is talking about something which is transmitted from one person to another. I suppose that in regards specifically to art, both theories discuss the transmission of the feelings from one person to another. But then again, every theory of art discusses this transmission, so to say that the two theories are similar in that regard is to say that every theory of art is similar. At any rate, these two theories discuss different ideas--Nietzsche is talking about internal emotions which are aroused in each man individually, with no mention of the intent of the artist, whereas Tolstoy says that if a man makes a piece of art from his own emotion, it will be transmitted to another man by the force of that emotion. The transmission of feeling evoked by art is completely different.