Microsoft's initial stock of Surface RT devices has sold out in the United States. The 32GB base model, at $499, sold out earlier in the week, but all stock has now been depleted with a wait time of within three weeks rather than a guaranteed October 26th delivery. Alongside the sell out, a number of UK readers are reporting that Microsoft has delayed the release of Surface by a week.

"The release date for the preorder product has changed," reads an email sent to some buyers who pre-ordered a Surface in the UK. "The product listed below will now be available on 02 November 2012." It's not clear from Microsoft why the Surface is delayed in the UK, but we understand from sources that it could be due to units being held by UK customs. Microsoft has started taking pre-orders for Surface at its retail stores in the US, with a "limited number of reservation cards" being handed out for the release on October 26th. We have reached out to Microsoft for clarification on the November 2nd release date and we'll update you accordingly.

Update: Microsoft has confirmed the email was sent in error to some international customers. "All customers should expect their devices by the original date given when orders were placed. Microsoft is following up with customers to confirm their original shipping date remains unchanged, and we apologize for any inconvenience caused."

Thanks, Paul!