Jim Naughton does the "Lambeth Math" over at Episcopal Cafe:
According to conference planners, more than 650 bishops have registered for the Lambeth Conference. That's slightly more than three-quarters of the invitees. A small number of sees are vacant, and some bishops have scheduling conflicts or simply cannot attend. It is difficult to learn which absentees are part of the Nigerian-led boycott, and which simply aren't coming, but the boycott may account for some 20 percent of potential attendees.
The leaders of GAFCON claimed that some 280 bishops attended their gathering in Jerusalem, but in a telephone press conference on Monday, Bishop Martyn Minns was unable to say how many of that number were diocesan bishops currently in communion with the Archbishop of Canterbury. If the figure included signficant numbers of retired bishops, assisting bishops and bishops of groups that have never been part of the Anglican Communion, it is highly misleading. Daniel Burke of Religion News Service was the only member of the media who thought to question it, and it was his question that elicited Minns' response.
According to a recent paper by the Rev. Gregory Cameron, deputy secretary general of the Anglican Communion, some 140 of the bishops who were at GAFCON (and, one assumes, won't be at Lambeth) are Nigerians. If his numbers are right, Nigerians account for not quite two-thirds of the bishops who, for whatever reason, won't be at Lambeth.