The Xbox One was announced, and it’s coming later this year, though when exactly is still unknown. Before the holidays, probably in November—that’s pure conjecture on my part. If you want to know exactly when you can preorder, two options have already been put together. A preorder for your preorder, is what it is.
Per Major Nelson, you can either go through Amazon, or Microsoft’s own online store, which is offering $10 store credit. Microsoft was less than forthcoming about pricing or release details, but that’s to be expected this early on. We might hear more information come E3; the more likely scenario will be an announcement a few months before the console is actually available.