Yes, AES sent you that envelope (if it is the same one that I am thinking of) on behalf of Duquesne's financial aid dept. I got the same one about a month ago, and have since returned the enclosed forms (i think it is the note for the loan if I remember correctly and other info documents...). Once you return it, AES quickly confirms your loan amount, etc.
On the other topic, I am thinking about staying in Pittsburgh after graduation....since, it is obviously a better recruiting area for our school... and after some years, I might move...who knows! But from first impression, i really enjoy Pittsburgh and hope to for some time to come.