Depends on the Serial Number.
It shouldn't be greater than SEH1135. Everything under SEH1135 is pretty safe.
https://docs.google.com/spreadsheet/ccc?key=0AjP9tDhuJyoldHdJVlFZVnN6RUpWbERIcHdYRFR6MUE&usp=sharing#gid=0
Well, now I purchased a 3DS XL at Saturn in Austria.
Red/Black
SEH1034xxx
Copyright 2011
FW 4.2.0-9E
There were more than 10 devices left, which had a Serial-Number <= SEH1135 (afaik this is the greatest Serial-Number with a Firmware <= 4.5)
Wow, people here are very friendly. How should I now what FW is installed on the 3DS XL? I couldn't find the number on the Excel sheet, so I wrote it down here.
Bought a Nintendo 3DS XL Black on amazon.de (German Webpage) -
The serial number is SEH12162385 0
Firmware version 6.2xx.
Copyright 2013
-> going to send it back. I could also see that someone else had unpacked the package before me.
Regards from Austria