Still, the question of whether Mac or Windows is more secure is no longer relevant. The computer security paradigm is shifting at this very moment. Cloud computing, Web 2.0, and mobile technologies are exploding, and with those changes, traditional attacks are making way for a new crop that ignore platforms. Think ANSI bombs, boot sector infectors, macro viruses — seen any of those lately?
via No contest: Mac vs. Windows security | Security – InfoWorld.