Not sure if this is mentioned elsewhere -- the "Walk Around Companion" is listed in Bachmann's webstore. The interface panel is sold separately.
http://shop.bachmanntrains.com/index.php?main_page=product_info&cPath=264_274&products_id=1821
Interestingly the Smart Interface is not listed. Hmmmm.....
I have the wifi interface on Backorder from an Internet seller. Bac #44928.
When I ordered it they were saying fall delivery. It has now been updated with late July delivery.