IMO it would be in Sony's best interenst to launch at least one full week before the Xbox One. That would make the last week of October/First week of November perfect.

seems legit.

Amazon has Xbox One pegged for the 27th November
http://www.amazon.com/Xbox-One-Console-Day-Edition/dp/B00CMQTVK0/ref=sr_tr_sr_1?ie=UTF8&qid=1371838325&sr=8-1&keywords=xbox+one

Amazon.fr has it down for the 30th, so I reckon we are looking at the following

13th November: PS4 - US and Europe
27th November: XB1 - US
30th November XB1 - EU

Advantage Sony if this is right. You would assume these are going to be supply constrained, hopefully Sony can get a second shipment in by the XB1 launches and the weekend of Thanksgiving and Black Friday

probably. Can you imagine if Xbox One and Playstation 4 came out on the same day? That would be madness!