Just like any other OS that has ever been created, eventually, it will be populated by malware. How does the saying go, the only way to not get your computer infected is to not turn it on? Well, the authors of the OS must have their heads in a box if they think that it will be protected from malware. It would be the holy grail of all OS'es, not that it is a bad thing mind you, but I don't think that the technology is out there yet.
One day, we ever had a debate that the number of virus' out there are probably created by those companies that create the virus scan databases, like McAfee and Symantec, but then you read on how far behind they are in creating the fixes for those viruses and it really makes you wonder.
No, I don't think that any OS will ever be fully protected from malware. It is one of those things that is a fact of computer life that we all have to face up to and ensure that we keep our security systems updated on a daily basis. But again, this is just my opinion, free speech and all.