What Gün Sirer did in Vegas did not stay in Vegas: Sirer was a speaker at Hasher's United, the first-ever conference aimed at bitcoin miners and mining companies. He is quoted by the CoinDesk news service as stating at the panel, on how game theory can impact cryptocurrency mining, about the risks of 51% attacks by mining pools, "There is nothing to push it back except social pressure".
Sirer was also quoted on the Blockchain wallet breach, noting about the security issues the firm is suffering, "There is no room for the smallest screwup, and we're finding out that standard practices that are normal in Silicon Valley are unacceptable in the bitcoin world because there's so much at stake."
Sirer has a longer recent piece on the security of bitcoin at; the post also mentions Bob Constable's NuPRL project.