The device upgrades your old set to the same capabilities as LG's current smart sets.
We've seen plenty of set-top boxes like the Boxee Box, Revue and Roku. In that sense, LG's new ST600 is nothing new. It's not marketed in the traditional way though, with LG pushing it as an upgrade rather than a standalone device.
The ST600, which will be officially unveiled at CES next week, lets you access all the content that a connected LG TV is capable of. It also gives users access to LG Apps which have a broad range from educational programs to games.
LG hasn't named a price for the ST600 yet, though they have said they plan to make it affordable. Another mystery is whether or not the ST600 can be used with non-LG sets. From the press release it sounds like anyone will be able to use it.