Just for the record, Glocks are NOT made in the USA. They are made in Austria. The Tenifer coating process would give the EPA fits! The Tenifer coat is one thing S&W did not copy off of Glock because it couldn't be done "green" enough for the EPA.
The Georgia plant does one of two things. It is either a distribution point, most likely. Or it is only an assembly point for parts out of Austria. There is some debate over this. However, I find the first explaination most likely because of certain hoops Glock had to jump through to get pistols enough "import points," especially with the compact models.(ie finger grooves, adjustable sights, etc.)
Also why would they ship parts that have to be matched, the bbl, slide, and reciever all have the same serial number on them, seperately just to be assembled here?