Upgrading Reports [AX 2012]

MorphX reports as well as ReportLibraries can still live within AX 2012. There is actually a process in which you have to execute that will take the metadata for the AX 2009 ReportLibraries and update them, so they can live and execute within an AX 2012 instance. That resource can be found here.: Report Project Upgrade [AX 2012]

Guidance when upgrading the report
http://technet.microsoft.com/en-us/library/gg724106.aspx