http://arstechnica.com/security/2014/06/bitcoin-security-gua...
http://www.reddit.com/r/Bitcoin/comments/284me8/instant_conf...
Not to dismiss the 51% issue but that would affect all transactions, this -'instant protocol' is on top of bitcoin, not in replacement of.
http://arstechnica.com/security/2014/06/bitcoin-security-gua...