I've been to several funerals where the person was cremated... they displayed the urn on a table as a "viewing". I don't think too many people want to be displayed whole and cremated later, although... I am positive someone has done it. Isn't there a rule about re-using a casket?
But you don't need a fancy casket to be cremated in, a cardboard box is fine. I like the idea of friends and family decorating it as well... I mean, death is a fact of life and while we mourn the loss of someone we love, we also assist them into the next plane by giving them a personal send-off, yes? Yes. It's not morbid in my opinion, since I'm pretty sure this life is just a stepping stone.