new Microsoft Security Essentials 2.0 released 16 December 2010 installs and works on Server 2008 x86/x64 and on R2 too !
Desktop Features dont need to be on. If they are then it will disable Defender like in Vista / 7.
No tricks, no patching 😀
Tested myself with fresh install of 2008 x86 Enterprise SP2 – screenshots :
No other features or updates prior installed. Installation is quick, one reboot later it fetches the signatures from the web. Faster and less consuming as version 1.
People running R2 confirmed to me it works there also.