And, because the management-data exchange protocol Project Kendro uses to get Microsoft's Virtual Machine Manager to hanle Project Kensho implementations is the open-standard Common Information Model, any other systems manager that supports CIM could do the same thing.
No one else has weighed in so far to support Project Kensho, and probably won't, at least publicly. But any company in the datacenter business that is not either VMware or Microsoft stands to benefit from the change in focus Citrix is trying to promote.
So, whether it's in the way they package and offer professional services, bundles of virtualization-supporting applications, or in the way they advise customers to arrange their data-centers and design virtualized applications, you can be other vendors will support any idea that will weaken the idea (and reality) that any virtualization project must first start with products from either Microsoft or VMware.
It will confuse the comparative us-vs-them simplicity of a market in which there are two inimical, dominant players and a host of also-rans; but it will also benefit customers who will get better products, services, prices and less pointless marketing rhetoric than would be the case if every conversation about virtualization came down to which hypervisor company the customer decided to hire.