On an Anglican site I read the following:
Some believe that the Last Supper was a seder, but there is much evidence that it could not have been a seder, and was just a communal meal occurring close to the approach of the passover celebration. Many think that Passover seders should discouraged in Anglican churches because Anglicans are an Easter people who celebrate the passover from death into life at the great Easter Vigil. Others believe that Christians should hold seders, thinking that this was Paul's intent with the words 1 Corinthians 5:8: Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened [bread] of sincerity and truth.
However, I ran the following search (Passover, Seder) WITHIN {Milestone <1 Cor 5:8>} and found several hits but none that interpreted Paul as encouraging the celebration of the seder meal. Anyone know of a source that does or a better search to find one?