Seems like a simple Kanban (http://en.wikipedia.org/wiki/Kanban) board. I'm not sure why this is new, there are a lot of options for Kanban out there.
Most of the kanban boards out there worth their salt cost some serious pennies if scaled to a large team!
plus... as far as I know Trello doesn't have the functionality for WIP Limits
This board also integrates nicely with GoogleApps, if it has integration with tfs (not sure if it does) then it would stand a good chance of owning a piece of the PM scene in .net land