XenSource gets the short end of the stick

The blogosphere is all abuzz about the Microsoft/XenSource deal, praising Microsoft for trying to "get along" with Linux. "The Wintel days are dead" according to Dana Blankenhorn. Jeremy Reimer writes that Microsoft "has acknowledged the fact that it is a heterogeneous world out there". Has anybody but me actually read the press release? Compare this part:

The next version of Windows Server, code-named "Longhorn," will provide customers with a flexible and powerful virtualization solution across their hardware infrastructure and operating system environments for cost-saving consolidation of Windows, Linux and Xen-enabled Linux distributions. 

with this part:

For customers with Premier-level support agreements, Microsoft will use commercially reasonable efforts to address potential issues with Microsoft software running in XenEnterprise.

Translation: We'll let Linux run better under Windows Server, and if you pay us enough we might address problems with Windows running under XenEnterprise.

VMWare (a XenSource competitor) is understandably biased against the agreement. But it's hard to argue with VP Brian Byun who wrote:

It’s a one-way street that favors Microsoft and Windows running Linux. The arrangement will allow Linux to run on future Microsoft hypervisors through translated calls to the hypervisor when Windows is controlling the hardware, but not the other way around; i.e. there is no mention of Longhorn optimizations or "enlightenments" being ported to Xen or licensed to XenSource to enable a Xen hypervisor to run full optimizations with Longhorn OS.

In reality, XenSource didn't have a choice. Because Xen and Linux is open source, Microsoft or anyone else could read the code and figure out how to make Windows Server a better host for Xen-enabled Linux. But still, the agreement rings hollow.