In the past, data architects/modelers have been primarily responsible for preparing logical data models, then they threw models over the wall to the DBAs who said "WTH is this?" and then did their own physical models (or reasonable facsimile of a model), generated DDL, and never used the models again.
But I think responsibilities have shifted. I want to see data architects that understand enough about physical design and performance to be able to participate and model performance and other physical aspects in physical data models. I think a professional data architect should be able to generate first cut DDL and understand the implications of PK selection, index strategies, etc.
What do you see happening on development projects now?