There is indeed a NDA for this beta atm however david has been on interview with a few ppl while they played the game and asked any live streamers questions while they played it. http://www.youtube.com/watch?v=L3eFS52jpso = by gamespot
https://marvelheroes.com/news/news-articles/marvel-heroes-athene-livestream-preview = Athenes Marvel hero live stream session.

Other then those two ppl no other player/streamer has been given permission yet to live stream any game play yet.