Our priority is ensuring our customers get the best Xbox One experience the first day it is available. To do that, and in order to meet demand, we have adjusted the number of markets that will receive Xbox One in November to 13 markets, including Australia, Austria, Brazil, Canada, France, Germany, Ireland, Italy, Mexico, Spain, United Kingdom, United States and New Zealand, in November.
We remain committed to launching Xbox One in Belgium, Denmark, Finland, Netherlands, Norway, Russia, Sweden, Switzerland, as soon as possible in 2014.
While we wish we could launch Xbox One simultaneously in these markets, there are many factors that determine the timing of specific market launches. This includes work to localize the Xbox One dash, incorporate additional voice and languages, and build partnerships to bring apps and meaningful local content to each country.
We understand this will be disappointing news for our fans in the impacted countries, and we are doing everything we can to bring Xbox One to you as soon as possible next year.
If you are in these markets and have questions about your pre-order, please contact the local retailer where you placed your pre-order. To show our appreciation for your patience, if you have already preordered an Xbox One Day One system before today in those countries, you will also receive a pack-in game with your console when it launches.
Source and more info: http://news.xbox.com/2013/08/xbox-one-confirmed-markets