Desktop PCs can always be reimaged. It's a pain, but downtime only affects one person. Servers, on the other hand, need to be up the vast majority of the time. Rebuilding servers affects lots of people, often in mission-critical ways. While most servers don't spend much time browsing the web or receiving emails, some have quite a bit of exposure (terminal servers, for example, that handle web traffic for entire labs).
While every Windows server obviously needs anti-malware protection, terminal servers and others providing virtual desktops or remote access could clearly benefit from the real-time protection promised by Microsoft's Morro project (now officially known as Microsoft Security Essentials). There are those, in fact, who see it as Microsoft's responsibility to provide malware protection for all of its products, given their penchant for attracting malicious code.
Unfortunately, MSE is only available for Windows XP, Vista, and 7. No mention of servers. No Googling suggested that server support is in the pipeline. While Clamwin does a perfectly adequate job protecting servers, full-blown server anti-malware solutions aren't cheap and, again, lack MSE's near real-time updates.
Then again, would you entrust your mission critical servers to a Microsoft anti-malware solution? Take the survey and talk back below.