The Catholic Knight offers some speculations

Most interesting, especially the comments section!  Here's an excerpt:

This condition of a non-episcopal Ordinary is in all likelihood a temporary one.  It is designed to prepare the way for something different later on.  Originally, when traditional Anglicans first opened communications with Rome, the idea was to create a whole new rite for Anglicans entering the Catholic Church, however, this proved impossible at this time because of the condition Anglicanism currently finds itself in. In order to have a full-fledged rite, there must be celibate bishops with real apostolic succession, an undisputed patrimony, and no ambiguity on the sacrament of holy orders.  Historically, Anglicanism has not possessed these things, in any clear fashion, even though it has demonstrated an certain affinity toward English Catholic liturgy and sacramental life. 
So what the pope did was create an incubator called the 'Anglican Ordinariate.'  It is similar to the military ordinariate for Roman Catholics.  The idea of the Anglican Ordinariate is to create a 'space' (if you will) within the Catholic Church, wherein traditional high-church Anglicans (i.e. Anglo Catholics) can further develop their patrimony with absolute clarity, in an environment where holy orders are no longer in question. The position of Ordinary may be occupied by a married priest for as long as these Anglo Catholics require one. However, it is envisioned in the long run that there will be some celibate men ordained into the Anglo Catholic priesthood eventually. These men will eventually become candidates for the position of Ordinary when the time is right. When that day comes, a celibate bishop will be consecrated as the next ordinary (someday in the future). Once that happens, the ordinariate becomes a 'particular church,' a full-fledged diocese (if you will), and the Anglican patrimony is well on its way to become a full-fledged rite within the Catholic Church, just as soon as all the ordinariates worldwide are similarly prepared.
As for time frame, your guess is as good as mine. Speculatively, one would think one to two generations would be ample. However, that is not a job for this pope or this generation. This pope plants the seeds of a future Anglican Rite. Another pope, someday in the future, will harvest the crop, and actually make it happen. Just as Pope John Paul II cleared the field with the Anglican Use Pastoral Provision some thirty years ago, so this pope (Benedict XVI) is laying the foundation with the Anglican ordinariates. Other popes will help build the structure as Anglo Catholics supply the living materials, and someday the Anglican Rite within the Catholic Church will be completed.  Personally, I would think at least thirty to forty years will be required before this happens, perhaps longer, but you never know.  The Lord works in mysterious ways.