I don't think this has been touched on yet, but along with the changes in features for this year, now there is no "AO" code for 2015 kettles. Weber appears to be moving to an all individual serial number format for this year. The serial numbers actually started in 2013 with certain models like the Performers, 26"ers and WSMs.
Here's the breakdown of what to look for:
It's still date coded in the serial # with a prefix denoting the years:
CN####### = 2013 (AT)
CS####### = 2014 (AH)
CU####### = 2015 (No two letter code)
So with this format, this would change our reference to 2015 kettles as CU code/serial. Just some things to look out for when scanning for kettles and determining their age. This marks the first major change in serial/date coding by Weber since 1979.
This is from a 2015 Copper One Touch Gold on display at Lowe's last week.