One of the 'post voyager' concepts tapping around my brain was that of the Delta Federation... A loose conglomerate of worlds and allies along a long corridor of space all of whom were influenced by Voyager. There seemed to be a fair amount of potential, ironically enough stemming from 'Ambassador' Neeliix who was clearly left behind with Federation tech and training and from the Pathfinder project.
Such member worlds might include Talaxians, post-phage Viidians, the Borg Cooperative to name just the first three of the top of my head, also seems to me that a number of the very minor species might also be inclined toward this ideal too and I never got around to detailing the minutae. Ocampa may well also end up on the list as the Delta Federation would be likely to encompass the planet once the idea had spread that far.
Of course this alliance might not be quite as 'enlightened' as the UFP and while meaning well might sometimes get things wrong. Could make for an interesting adversary in a Delta Quadrant game and enable a few curve-ball throws at players who think they know what to expect!