As evidence that major security vendors already understand this emerging shift, the experts highlighted the fact that more than 20 such companies immediately signed on to help support new systems-defense tools from virtualization market leader VMWare, even though the technology being pitched is still under development.

"The concept of re-perimeterization will involve taking the [existing] perimeter and making it stronger, condensing it in places, and adding all sorts of little internal perimeters," said Mogull. "It's not that the perimeter will disappear soon, but it will consolidate. Companies don't have a choice about this; with remote workers and virtualization, this is already happening today."

However, perhaps the biggest shift in IT security is one that is already transpiring around information protection, as companies shift their primary focus away from systems defense to safeguarding their valuable data.

Both experts are endorsing an approach they have labeled as the "info-centric lifecycle," through which companies will create mechanisms to secure data from the time it is created until the time it is destroyed, with different tools and policies involved for protecting information in every phase of its existence.

In another Source conference session, Yankee Group analyst Andrew Jaquith set forth the strategy he feels that anti-virus vendors must adopt to make their products more effective at stopping today's increasingly complex and customized malware attacks.

With malware authors already creating so many variants of their attacks, the result has been the equivalent of a denial-of-service assault leveled at anti-virus research labs, which can't possibly hope to write signatures fast enough to keep up with all the new threats, the expert said.

To help address the problem, the analyst contends that anti-virus providers need to move beyond the current defense model that emphasizes attack prevention and push their products and services further into attack detection and response.

So many threats are evading the traditional preventative approach used today that the transition must be made rapidly, with vendors moving to adopt their own in-the-cloud hosted anti-malware capabilities for identifying and reacting to attacks more quickly. More emphasis should also be placed on sharing information between anti-virus providers, the analyst said.

The continued adoption of a "herd" model among anti-virus systems that employs threat profiling on widely distributed end-point devices to gather information on new attacks, and central repositories of such data maintained by the vendors, will be another crucial element of future defense mechanisms, said Jaquith.

"Where we need to go from an industry perspective is to de-emphasize prevention, versus some of these other elements; vendors need to discover telemetry and [examine] applications running our machines and use that information to build better software, compared to the top-down, no-feedback model we have today," Jaquith said. "The current situation isn't working; malware defenses are not keeping pace and threat profiles are a lot different; the top-down model is a weak link."