I Suspect the WTIU is just around the corner. Explorers & WIU's are now back in stock. So long for the scalpers on eBay wanting 300 to 500 bucks for a used WIU that you can now get at Trainworld for $169: WIU at Trainworld
Also curious, Did the WIU go through a redesign? Some vendors are posting pictures of it in a slightly new housing: