Microsoft has announced the release (or eminent release) of the SQL Server 2005 SP2, that enables integration of Reporting Services with WSS 3.0 and MOSS 2007.
“Microsoft SQL Server 2005 SP2 . . . ,enables deep integration between Reporting Services and SharePoint technologies (Windows SharePoint Services 3.0 and Office SharePoint Server 2007). This integration enables an end-user to view and manage reports completely from within a SharePoint environment . . .”
You can find this annoucement here.