The question of Lambeth 2008 and its narrow terms of attendance and the narrow basis of a Covenant does require responses from such groups and bishops associated with them, such as Inclusive Church, Accepting Evangelicals and the Modern Churchpeople's Union. The issue is whether bishops are going at attend and, in effect, be subversive, or whether they take the stance of staying away, recognising the change in the situation represented by the Advent Letter of the Archbishop of Canterbury.
Changing Attitude has published a response. Its focus is rightly on the LGBT people it represents. It is worried about a further fracturing Communion, which would be a criticism of staying away from Lambeth 2008. The danger is that fracturing leaves LGBT people in very unfriendly cultures to potentially harmful Anglicanisms breaking away. However, it sees that LGBT people are being left as second class citizens on the basis of the Advent Letter.
What I'd say to this is that the Advent Letter is not only a present day fix, but is an attempt to fix the present day into the Instruments of Communion and how they operate. This is really rather different, and should be actively opposed by Changing Attitude. It is responding as if it is still hopeful - for example that a better Covenant might be an outcome. I don't see it from the terms and conditions laid down about the agenda and about attendance. Changing Attitude says Lambeth 1998 1:10 cannot be the final word on LGBT inclusion: but not only is it being treated as a final word, it is being bedded in, and a key part of the intended centralised Communion. Changing Attitude wants all bishops invited to Lambeth 2008: look, they are not going to be invited!
The choice may have to be a Communion in which LGBT people are set up as hidden people, or at least (eventually) a smaller Communion where LGBT people play a full part, are heard with everyone and are a full part of Anglican witness. Will they be more effective as a hidden people, across the globe, unable to have any expression of approval given in ritual and ministry, or more effective able to be fully part of an Anglicanism that is loose, plural, open, with blessings for relationships, and openly LGBT throughout the ministry?
I don't know: what I do know is that the terms and conditions of Lambeth 2008 for its agenda and attendance are too narrow for anything other than a predetermined outcome.