Actually, Rowan Williams was very clear on some important points:
1. Some actions – and sacramental actions in particular - just do have the effect of putting a Church outside or even across the central stream of the life they have shared with other Churches.
In other words, with its actions the ECUSA has placed itself outside of the Anglican Communion, and (as he says elsewhere) -- it is simply not possible for the ECUSA to claim on its own that it is still "in" despite its having taken its current position.
2. The idea of a ‘covenant’ between local Churches (developing alongside the existing work being done on harmonising the church law of different local Churches) is one method that has been suggested, and it seems to me the best way forward.
Which is to say, the ECUSA (and Canada) have shown that "collegiality" is no longer enough to hold the Anglican Communion together. A more formal structure -- presumably with actual authority -- is needed, and will most likely be defined and agreed-to at Lambeth.
3. He provided a very succinct summary of what, precisely, the Anglican Communion is (and is not); and why it is important that the Anglican Communion exist.
These are very clear statements and prescriptions. Say what you will about the man, but he nailed this one.
And, of course, I speak as an "outsider," but I don't see how, if you follow what he's written here, that anything like an Anglican Communion exists.
An Anglican something, but surely not a Communion in any traditional theological sense of that term?