My son will be finished with his deferred adjudication for two misdemeanor possessions of marijuana on May 11, 2008. I would like to know what are the procedures for his release from deferred adjudication since his PO has not been very clear on what is going to happen? Will he have to make a court appearance?

Normally yes there will have to be either an appearance or a motion filed and signed by the judge ( sometimes done without court appearance)

This is the common and normal procedures in the courts I have workded at. You should check with the clerk of the court where this was heard at originally