I saw Xbox Ones in multiple stores before Christmas without even trying to look for them.
They've also been up on amazon for a while now http://www.amazon.com/Xbox-One-Console/dp/B00CMQTVUA/ref=sr_1_1?ie=UTF8&qid=1388541755&sr=8-1&keywords=xbox+one
Perhaps it's different in other regions but I wouldn't use lack of supply as the reason for this.