In fact they launched their last AR watch in 2011, it was the 5550.
I asked myself the same question and I'll try to learn something more during the next 2015 collection presentation in Paris.
Thanks for your comments Robin 
Cheers, Mark
Edit : After I read CH's answer I realized I didn't answer correctly to your question, I thought you talked about "since the last one in 2011" but you seem to have asked "since the launch of the first one in 2005". I was too fast reading, sorry :p
I can give you the link of Dje's post made in 2011 which is very complete and clear:
patek.watchprosite.com
This message has been edited by Mark in Paris on 2015-04-19 08:11:22