The UK National Archive supports the "doomsday" reading (http://www.nationalarchives.gov.uk/domesday/discover-domesday/) which surprised me as I figured it "domesday" like domestic as in local, home, counting chattels, etc.

/u/joustswindmills has it! "Doom" (as dome) refers to a legal reckoning in Old English. It gets the modern sense of a terrible fate as a result of being associated with the Christian Last Judgement. The Online Etymology dictionary has entries for both "Doom" and for "Domesday Book" where it gives a great quote from one William Lambarde, writing about the name in the 1570's, saying ""The booke ... to be called Domesday, bicause (as Mathew Parise saith) it spared no man, but iudged all men indifferently."