SBS 2008 will support 16 cores.
I know this isn't official, but it's a page of people that have tried it succesfully ;
http://blog.mpecsinc.ca/2009/09/sbs-2008-and-16-cores.htmlhttp://www.microsoft.com/windowsserver/essential/sbs/editions.mspxThis page talks about a 4 socket limit
http://www.microsoft.com/windowsserver2008/en/us/compare-specs.aspx1 quad core in each socket = 16 cores.