Microsoft Dynamics AX 2012 won’t support Oracle database. It was only a question of time and the time is here now.

Current customers using Oracle database as their AX transactional database will be forced to switch to Microsoft SQL Server. It should be facilitated by Oracle to Microsoft SQL Server Data Migration Assistant for Microsoft Dynamics AX (PartnerSource link) – it allows to migrate AX4/AX2009 databases; conversion of Axapta 3 database is supported as a part of upgrade to AX2009.