"Full support of application-level administration and load balancing for Windows platforms is not yet in the IBM roadmap," Kernochan writes. "And as for full integration of Windows platforms with the mainframe in a private cloud, that's at the very least not yet in the roadmap, and perhaps a goal that may never be reached."

Still, he adds, "This does not mean that IBM's planned support for Windows on zEnterprise is incomplete. On the contrary, IBM has applied its usual combination of strong technology and services to allow users to implement IBM System x blades running Windows that integrate seamlessly into the overall zEnterprise solution."

Kernochan also discusses the value of integrating Windows, Linux and IBM's z/OS mainframe operating system.

"If we can imitate enough of Windows on Linux or on Linux-supporting blades, we can move most Windows apps to scale-up servers when needed (Unix/Linux and/or mainframe)," he writes.

Third-party vendors will make tools to treat Windows virtual machines "as just another system for purposes of backup/recovery, monitoring, load balancing, and distributed-application creation," Kernochan writes. Those tools won't be ready in 2011, but "even with these limitations, IBM's promised Windows support will be immediately valuable to many organizations," he writes.