At Pwn2Own an attacker used a chain of three exploits to penetrate three levels of security around InternetExploder8. It took him weeks to get around randomized location of software but he did. Others might see this as reason to add another layer of security. The hacker earned $thousands per week for his efforts. A malware artist might have earned $millions. I see this as an indication that M$ creates so many holes with each addition to its software bloat that smothering the software in layers will accomplish little. They might even make the software less efficient.
No one even bothered to attempt to crack Google’s Chrome. Even if Chrome could be penetrated if it is running on GNU/Linux there might still be a layer of security left. Bill Gates integrated IE so tightly with that other OS that if you own the browser you own the PC, and the network, and the server, and, soon, the cloud. No new layers of obscurity will protect that other OS from its fundamental flaw, that it was conceived as a single-user system.