No problem; glad I can help.
Well I guess a lot of people think that IFPS is planning to take over the entire world, but the reality is the we are governed by politcal masters, so I suspect there won't be too much more expansion. However, having said that, after its primary function of providing flight data to the ETFMS (check the website acronyms page!) for flow and capacity control, the other function of IFPS is to rationalise the reception and distribution of flight data messages, and to ensure that message filers are in compliance with requirements laid down by those states employing a full IFPS service, so no real reason why IFPS can't continue to expand, or the concept be used by indivudual or groups of states. That's all pure rumour with no known substance though, so don't hold your breath or have nightmares!
FP3 and FP4 - no plans as far as I know.