I do not want to downplay the quite valid feelings and scruples of the folks who call themselves "orthodox Anglicans." But let me give you some background:
Back in 1979 we agreed to ordain women as priests and adopted a new, modern language Prayer Book -- the basic text from which our services are produced. There was enormous controversy over both acts, and threats to secede. Eventually some people did -- perhaps 10,000 or so.
The decisions last year at General Convention which prompted this latest furore were passed by majorities approximating two-thirds each of the bishops of the church, the delegates representing the ordained clergy of the church, and the delegates representing the laymen and laywomen of the church. All these were indirectly elected by the local churches -- being chosen by diocesan conventions whose members were elected by the local churches.
From listening to people on all sides of this argument, I'd have to say that the majority of the church may be pained at the decision made but will stand by it. About a third of the church's membership is opposed to what was decided, but the majority of them seem to hold the view that they should not leave.
The Plano group has a very thorough public relations program, and consists of a very vocal minority -- a significant minority, perhaps 10% of the church -- but still a minority. Its leaders are four bishops (Duncan of Pittsburgh, Howe of Orlando, and the bishops of Fort Worth and Quincy) who have been extremely outspoken against the majority view, and who seem poised to become "the big frogs in a small pond rather than being small frogs in a big one." (I.e., their egos have more than a little to do with their secessionist attitudes, IMHO.)
The Episcopal Church is and has been the U.S. national member of the Anglican Communion for 225 years now, and the Archbishop of Canterbury, whose job it is to lead the communion as a whole, has indicated that he will not "unrecognize" it.
The American Anglican Congress is a group dedicated to preserving traditional beliefs, behavior, and morality in the Episcopal Church and opposed to this sort of schism. And they're the group that the majority of conservatives in the church are affiliated with.