After spending far too many hours trying to set up pre-paid iPhone directly with AT&T, I decided to take matters into my own hands this evening. Instead of trying to connect my newly provisioned AT&T account, I iSigned up using iTunes and entered 999-99-9999 as my social security number (as recommended by one of the more clueful AT&T people).
Of course, this failed the credit check and I was offered the prepaid plan. I selected it, agreed to the terms, and pretty much 1-2-3, I was put into the activation queue. At this time, I'm getting the "Your activation requires additional time to complete"/"You will receive an email confirmation", but my iBrick has taken some major steps forward in its uselessness.