Looking at the likely GAFCON agenda then, and the now almost full (less Nigeria, Uganda) composition and method of Lambeth, with a full liberal (less the famous one) turnout, here is what is likely:
GAFCON participants get all puffed up after their conference in Jerusalem, and there is plenty of output from there via controlled press releases and, more importantly, personnel, led by Bishop Gregory Venables, who come and tell Lambeth it has but one chance to, as they'd see it, get the Communion's house in order. The small groups of bishops mangle the material out of which a Covenant emerges, more restrictive than would be the case, as there is a shift to cover the GAFCON territory. There is audible disagreement as well as some attempt to pull together. Then the continuation group take the Covenant to a final draft, at which point a number of synods and bishops in their Churches start to say no again, as it stands (especially those who would be on the receiving end), and point out that in any case laws and constitutions prevent its imposition.
The Covenant ends up stalled, as it is unacceptable in many Churches and adopted in a number and ignored by the GAFCON provinces and supporters who declare that Lambeth failed to meet the challenge it set. GAFCON turns into the Instrument for Global Anglicanism.
The result is a wreckage worse than if the policy had ever been introduced, and results in recriminations because now there is no policy. The Instruments of the Anglican Communion are basically duds.
Anglican Churches make their own agreements with other Churches. The Communion becomes so loose that the principle of geographical monopoly is abandoned as the autocephalous route takes hold either by accident or design. The Lambeth Conference is finished as a ten yearly gathering, replaced by friendship gatherings according to Church generated agreements.
The Covenant is forgotten and an Archbishop has nothing further to say. The Instrument for Global Anglicanism starts recruiting bishops and congregations from within Western Anglican Churches, and reciprocal actions lead to the IGA becoming increasingly independent, revealing terrible strains within between its conserving Anglo-Catholics and its Conservative Evangelicals. Open Evangelicals are divided between the new grouping and the old, shattered that the Communion is so completely weakened, yet seeing that the new grouping will probably split itself.
So, in advance, the only Covenant that will work is an ineffective one in terms of its purposes; that already the ACI knows it is now a means of division as a solution to division; and that some people had better start thinking about how to organise Anglicanism according to an autocephalous understanding based around the Churches. The Covenant policy was a disaster from the beginning: maybe some at the Lambeth Conference can suggest something different - in keeping with the purposes of the Conference! As for GAFCON, it will just need to be deliberately and systematically isolated and removed in order that it does the least damage.