Today System Center Operations Manager 2007 beta 2 was released. You can download it at Microsoft Connect. You can find FAQ about SCOM 2007 here I have installed SCOM 2007 in Hyper-V and some commentary is

• Require SQL 2005 with SP1
• During the installation you can choose a security group that will be SCOM administrators. Local administrators is no longer SCOM Administrators
• You can change the name of the database, default name is OperationsManager
• Administrator Console is gone. In SCOM 2007 all operations is done from the same console, Operator Console. What you see and can do is controlled by roles. There is seven roles in SCOM out-of-the box. Administrator is the highest role and read-only operator is the lowest. A read-only operator can only read alerts and look at views in operator console.
• MOM v3 Command Shell, a great way to operate SCOM