The cloud solution coming later this year will still be based on Xen. We prefer over Xen over Virtuozzo because Xen fully dedicates resources (RAM, CPU, bandwidth, etc.) while resources on the Virtuozzo platform are not completely dedicated, although some may argue against that, not sure what they'd say but they may disagree.
The cloud engine software will be provided by our sister company, OnApp, and allow for us to give clients resources in a unique way; it will be more scaleable. Most clients won't know or ever see the software interface for the cloud because this is what controls everything on a global scale. It is cool, however, for clients to know they are on the most advanced cloud platform available, bar none!
The current cloud platfrom uses the same tech, as I mentioned before, but does not have the ability to scale up and down as needed. If you buy the smallest plan and need more resources you just upgrade to the next plan.
Does that help with your questions? I'd be happy to call you sometime as well if that would be beneficial to you.