In 2011 LG introduced the ST600 Smart TV Upgrader box (review here) and here is the successor. The new smart box is called SP820.
LG SP820 Smart TV Upgrader
LG has unveiled the SP820 Smart TV Upgrader box that turns every TV into a Smart TV – not just LG TVs. The box supports LG’s updated TV App platform and a range of internet services such as Vudu, Amazon Instant, and CinemaNow.

LG SP820 Smart TV Upgrader
SP820 also supports Plex. Plex is a media center solution based on DLNA technology. With Plex users can playback media files, including video, music and images from PC/Macs and handheld devices on the TV screen. Plex automatically adds text information and cover art to music albums and movies.
LG promises better and faster performance from the SP820 as well as a new, more elegant design.

LG SP520 Smart TV Upgrader
LG SP820 will be available from sprig 2012. A cheaper SP520 will also be available but we have no further details besides the picture above.