dbregman - They should.  The Microsoft Store here in Honolulu had spare charging cables.  
Indistinguishable - I guess results may vary.  My wife and I were at the store here in Honolulu on Dec 20, and one of the reps told us to come back on Tues, Dec 23 because they were expecting a shipment in.  She recommended that we get there when the store opens, because they sold out pretty quickly last time (inside of two days). So my daughter and I got there early that Tues and sure enough they had several in stock (L and S sizes only).  I picked up two, one for me and one for my wife as well as the free screen protectors.  The only thing they didn't have were the $5.00 Starbucks cards.  I will say, I am very happy with the Microsoft Store here in Hawaii.  They've been very helpful and knowledgeable every time I've visited.