The reason for hope we can have for the future of the series is that it might take a show or two to set up the new.... (firstthings.com)
A trend for the future of the series is set in which the original defining characteristic, while still in some lesser way characteristic of the series, is no longer the dominant trait. (religion-online.org)
While I find Shrek the Third to be entertaining enough to give it a pass in this regard, I fear for the future of the series, as now they've gotten even further away from the Grimm Fairy Tales / Disney world that the previous films spoofed, opening up the series to legendary characters and other tales of adventure. (qwipster.net)