McAfee ePO End-of-Life
McAfee has announced an "End of Life" (EOL) for ePO 4.x in December 2015. ABB currently recommends ePO 4.6.6 for the 800xA systems. McAfee recommends upgrading to ePO 5.1.x or 5.3.x.
What version of ePO will ABB be using going forward?
Probably the lastest stable - for official answer please file a regular support case with your regional ABB support center.
I upgraded the SE L3 lab to 5.1 some time ago (what a pain...). New install is probably less an effort since policies can be imported from templates at ABB Library.
I see very few differences in ePO version 5.1 compared to 4.6.