I ran the Episcopal Church stats through some tables provided by the NCHS. If things continue as they are, and barring any members actually leaving, the Episcopal Church will dwindle by 33% over the next twenty years. The numbers and percentage will likely be much higher than that.
The bottom line is a church of less than a half a million people. The future of the Episcopal Church is that of church closures and property sales.
Bishop Spong was right. The present Diocese of Newark is the future of the Episcopal Church.