The news out of Redmond is that Microsoft has struck a deal with open source virtualization software provider XenSource to allow Xen-friendly Linux operating systems to run atop the virtualization software that will ship with Longhorn Server next year.
The burning question is why Microsoft, which has been so vehemently against the "cancer" of open source, is now cozying up to providers like XenSource? As a writer at The Register points out, Microsoft is strengthening its alliance with XenSource so the two together can take market share away from VMWare. (Both MS and VMWare are giving away virtualization software to build a base in the burgeoning virtualization market.) It's the only way Microsoft can stay in the virtualization game while waiting for Longhorn to ship.
The software behemoth's agreement to support OpenDocument Format was likely driven by similar self-interest rather than warm, fuzzy feelings toward open source.