It has been finally released, Business Portal 6.0 for Dynamics GP 2013, it still does not support SharePoint 2013 but it has many enhancements could be found HERE.
Business Portal 6.0 is supported with the following: Click HERE to go to the System Requirements Page.
- SharePoint Server 2010 or SharePoint Foundation 2010 only.
- Windows Server 2008 x64 SP2 or later or Windows Server 2008 R2 SP1 or later.
- Internet Explorer 8.0, Internet Explorer 9.0, and Internet Explorer 10.0.
*NOTE:* SharePoint 2010 is currently not supported on Windows Server 2012 until the release of SharePoint 2010 Service Pack 2 due out this summer.
Below is the direct download link: