Uhm - this is a letter to the employees. Read the whole thing. Given that he backs up everything they do, he could hardly exclude the XBOX without sending a clear message of impending doom.
Also note that he motivates XBOX primarily through its benefits to other divisions. Take a guess at the internal discussions motivating his phrasing in the letter.
The real test of course is investor sentiment over the coming year to year and a half.
Amazing.
He could have not said anything about Xbox, instead of specifically raising a point about it and stating his confidence in continuing to promote and develop the product.