See Also - Small (Business) Server - Microsoft Windows Search or Microsoft Search Server 2008 Express
Can anyone tell me if they have Search Server Express 2010 Beta working on Small Business Server 2010, or indeed if it is supported. The only reference I can find is here, but given how scant it is I'm not sure I should trust it:-
If a Moderator on their own site says it does, i'd say you are safe to think it does, even if information on it is scarce as the moment. ;)
HTH