I'm not aware of any followup on the Hannity letters.
And I certainly agree with you that the style of the St. Petersburg letters is akin to the real New Jersey anthrax letters! And one of the cars involved in a bust there had Florida plates.
IMHO, we are likely seeing how an Al Queda operation works - with cells in multiple states and locations and some coordination between them. In this case, the terror is multiplied by the hoax letters intermingled with the real ones.
I didn't mean to dismiss the St. Petersburg letters altogether - only that the profile of the anthrax perp is a separate project from the profile of the hoax perp... maybe. The network may include both - or it may be the same perp! Hmmmm....
I suspect you are right that they have found no prints. And I suppose if someone saw a person mailing letters wearing rubber gloves they would have come forward by now. I was hoping maybe the fingerprints of the mail carrier who first retrieved the letter from whatever mailbox it was mailed from might be found so that the site of the mailing could be better pinpointed.