This is great news and long awaited - it was actually due to be built in 2007 however the sudden rush of EU infrastructure funding led the city council to have many other issues about developing the system.
The original route was to go down Marszalkowska to pl. Unii Lubelskiej, down Gararina, then down Sobieskiego. Interesting to see if they choose that route. It will be good for house prices, and Miasteczko Wilanów (plus the huge Stegny estate) will no longer be quite so cut off.
The largest single tram investment will be an entirely new 10km line linking the centre with the Wilanów district in the south of the city, which will also require 50 new trams to operate the route