Some context would be helpful. Is the a credible computer scientist, or just another crackpot? What has been the response of the mathematical community to thi

Some context would be helpful. Is the a credible computer scientist, or just another crackpot? What has been the response of the mathematical community to this? What, if any, are the criticisms of it? It looks like there have been a number of versions of this paper since last year: http://arxiv.org/abs/1208.0954 http://arxiv.org/abs/1208.0954 So, has anything changed?