iFolder was revolutionary when it was introduced. 2.x version on NetWare and the initial versions on OES and how they tied into the rest of system like NetStorage was superb.
iFolder 3.x based on mono - improved on 2.x in many areas like user experience, multiple folder sharing etc, but we lost some capabilities as well. Being based on mono had it's fair share of challenges too. However, iFolder has been in a maintenance only mode for the last couple of years, but that has helped us focus our efforts on Filr and get it to where it is today - almost on par or better than iFolder in most areas, more modern and better performing, with a road-map that takes you into the future.
iFolder is part of OES2015 and will be supported. But as we started work on the next major update to OES, in the above context, we started having some debates around the future of iFolder in OES.