I am assuming that it is a fairly new model as it came out with the other Z97 motherboards that had gotten released. If ASUS still has a page for it up it means that their is not a newer model for that one...weird newegg doesn't have it tho...
More Information:
http://linustechtips.com/main/topic/162117-asus-z97-ar-product-availability/
Quoted from Linus Tips:
AR series is a strictly business oriented motherboard, you will not find it in many consumer oriented retail shops or websites. Wait for at least 4 weeks to hit American retail stores.
Oh wow. I wonder if a business model would be good for a 4790k then. I'll be doing gaming on ultra
Good luck finding it other then at micro-centers. Newegg doesn't carry it but Amazon does...business rating motherboards I would assume are more for productivity vs. gaming. I would recommend the following: