There are a lot of rumors circulating this week about Microsoft changing their licensing policy from one where virtual machine is tied to hardware only to a model that compliments the mobility of virtual machines. Glad to see that they are rethinking its business model to keep up with virtualization.
The current policy requires customers to reassign software licenses for Windows Server 2003, SQL Server 2005 and Exchange Server 2007. The code would need to physically move to a different server. Please note that transfer between physical hosts are not allowed more than once in 90 days.