Update: Be sure to follow along with our liveblog of the event, starting at 10AM PT / 1PM ET!

Microsoft has started sending invites to members of the press for a Windows Phone 8 event in San Francisco on October 29th. The event was previously rumored, but Microsoft is making it official now by promising some additional details for Windows Phone 8 on the day. We already know HTC and Nokia both plan to introduce Windows Phone 8 devices in early November, but Microsoft's event appears to be the official unveiling for availability and could mark the beginning of pre-orders for handsets in the US. We'll be live from Microsoft's Windows Phone 8 launch event to bring you the very latest on the software secrecy and any additional hardware announcements.