Below is a link to the UGA beekeeping newsletter that states AHB are officially in FL -- Tampa area to be specific. They think they arrived not by eastward migration, but by ships or even brought in on purpose.

http://www.ent.uga.edu/bees/Newsletter/aug2005.htm

According to the State of FL, AHB swarms were intercepted 30 times in the past 22 years mostly on ships coming from Guatemala.

On a lighter note, there is a petition afoot to get a honeybee stamp. Here's a link.

http://www.beesonthebrain.org/