Having absorbed the details of the Vatican's surprise move to invite more disaffected Anglicans into the Catholic communion, it's clear that this is much more than merely allowing more married Anglican clergy to become Catholic priests.
It also allows them a kind of church within the Church, and an Anglo-Catholic liturgy, including the Book of Common Prayer, inside the Roman tent. The biggest impact may well be in England and Wales, where the more traditionalist Anglicans will now have almost no pastoral or liturgical reasons not to join Rome (although the theological and doctrinal reasons remain). The move was clearly sprung on the Archbishop of Canterbury - he tried to be as graceful as possible and was almost convincing - and essentially junks an entire tradition of ecumenical dialogue in favor of a quick and sudden merger and acquisition.
Rocco's take is the best, as usual. I presume it means full inclusion within the Catholic church (papal authority and transubstantiation included), which might have raised Thomas Cranmer's eyebrow a half inch or so.
The structure has yet to be formulated. In America, I doubt this will have a huge impact on anti-gay and anti-feminist Episcopalians, who have already had their own structure within the Anglican church and now outside it. In fact, I bet you the bigger impact could be a bunch of liturgically traumatized Catholics in England and America moving en masse to those sublime Anglican liturgies, if there are sufficient bells, smells, incense, and King James.