There is a fantastic discussion up on McAfee on "Security in the Post-PC World". Prompted by the release of Google's Chromebook, the article talks about how security must, and is, changing as the result of Post-PC devices.
Post-PC devices are small gadgets that run compact operating systems vs the normal general-purpose operating systems. As such, the security on these systems is more strict. As Forrester notes, 3 key characteristics of this model are:
Current malware won't be a problem for post-PC devices, though spyware will be. Data access and security will continue to be a priority, as the data centres that hold your personal data in online services will need to be protected.
It may be that the whole market is moving mobile, an exciting change. Security will never cease to be a problem, it will only change and evolve with each new device, operating system and use case. We're excited to be a part of this moving security landscape.