With cloud computing going mainstream and virtualization a core element in IT strategy, Cisco could be interested in acquiring virtualization stalwart Citrix, say the folks at Motley Fool. And in a time when Cisco is warming to the "unified" approach, a Citrix buy would give Cisco the ability "to build an entire data center on its own platforms."Citrix gained instant virtualization chops almost two years ago with with its $500 million acquisition of XenSource, which supplies the Xen open-source hypervisor. And earlier this year, Citrix deepened its credentials in the virtualization market by becoming a strategic investor in desktop-hypervisor startup Virtual Computer.

Here's how Motley Fool's Anders Bylund outlines the Cisco-buys-Citrix virtualization scenario in the context of Oracle's recent acquisitions of Sun and Virtual Iron:

"So now Oracle owns three different virtualization products: Sun's xVM suite, Virtual Iron's eponymous package, and its own Oracle VM. Curiously, all three solutions borrow the crucial hypervisor component, which helps you manage a multitude of virtual machines from a central point, from the previously open-source Xen project. Citrix Systems owns Xen now, giving that company a bit of leverage on what happens in the broader virtualization market.

"Of course, with VMware looming large over said market and Microsoft working hard to catch up with its Hyper-V line, that could make small-cap Citrix the next acquisition target here. Cisco Systems isnot afraid of buying its way into new markets, doesn't have any virtual machine software of its own, and could essentially build an entire data center on its own platforms with Citrix under its belt. Oh, and a deal for less than $10 billion (including a generous buyout premium) would be a mere morsel for ultra-rich Cisco," wrote Bylund.

At Interop this week, cloud computing and virtualization dominated much of the conversation, and the winner of the prestigious overall "Best of Interop" award was VMware's vSphere 4, which "emerged as the winner because of its outstanding innovation, industry-wide impact, and substantial improvement over previous generations," wrote the InformationWeek team covering the awards. So the virtualization market's not waiting for anyone to play catch-up, which could lend additional urgency to the Fool's speculation.