Feeding/Chewing

My son was diagnosed with autism in January 2009 and turned 3 in October 2009. He generally cannot feed himself except for finger foods/snacks that he likes such as Lays potato chips. He also does not like to chew so we have to blend most of his food and spoon feed him. Once in March of this year, I worked with him for a week to teach him how to hold a spoon and feed himself. It worked! He could feed himself rice and even his GFCF hot cereal (he usually made a big mess with the latter). Then around May, he just stopped and it has been very sporadic since then. He has regressed to the point that he even wants us to feed him his juice during meals :(
He will however pick up the juice cup randomly throughout the day if left in his high chair tray.
He also wants to eat the same thing for dinner every night and gets upset when something else is offered. When I am not home, other family members will give in and just feed him or let him eat the same thing all the time. He started school this November and has his IEP in place so I know he is going to receive some great assistance with life skills there. But in the meantime, does anyone have any ideas on how to get my son to start feeding himself again?