yuna49 (905461) writes "eWeek reports that "some of the changes in the upcoming release of Windows Server 2008 are a response to features and performance advantages that have made Linux an attractive option to Microsoft customers." The article cites Linux's smaller "surface area," which appears to mean having fewer exposed services and open ports. In addition, it appears that Windows Server 2008 will run without a GUI, as do many Linux servers now. Other areas where Microsoft is playing catch-up include clustering and web-serving.
However Linux, with Xen, appears to be less of a threat in the virtualization arena. According to the general manager of Windows server division, "We can tell which hypervisor they are running on and to be honest, I see zero on Linux. We see VMware rather than Xen because it's not really out there in production versions of Red Hat and SUSE. But the long-term issue around virtualization will be who had the best management tools.""