We have just released a hotfix that adds support for the Safari browser (version 5.1.2 on both Windows and Mac) for Enterprise Portal in AX 2012. This will further expand the audience of Enterprise Portal and Microsoft Dynamics AX 2012.
This support is mainly for end-users i.e. end-users should be able to perform tasks in Enterprise Portal successfully. Although system administrator and developers tasks should work too we are not officially supporting these.
You can download the hotfix from PartnerSource here: https://mbs2.microsoft.com/Knowledgebase/KBDisplay.aspx?scid=kb;en-us;2686124.