File this one under "strange bedfellows." The APA is largely "high church" Anglo-Catholic. The REC is mainly evangelical "low church." Which, BTW, is the reason behind their decision to abandon the initiative to merge these two groups. A substantial amount of the REC membership opposed that plan - apparantly in favor of this somewhat looser "confederation" idea. Add to these the AMiA, which is an amalgam of various expressions of Anglican worship (including parishes that continue to use ECUSA's '79 BCP), & you have an organization (FACA) that should be interesting to watch.
The union envisioned between the APA & REC has not been abandoned and is still moving forward. Is there some opposition within the ranks? Yes, as there has been since the agreement was first formulated in 2000 and the opposition is on both sides, not just the REC. This was, from the beginning, envisioned as a VERY slow process, intended to be at least a decade long. A Unity Synod has been set for 2008 to continue the process.
The FACA idea was the APA & REC taking the lead to try to get something done regarding unity among traditionalists to show a united front, responding to the call of the Global South Primates of the Anglican Communion, who have asked us to "get together." The AMiA apparently saw some value in this and decided to sign on. Other traditional bodies in the US have looked at this and are considering allying with it.