According to L'Essentiel, the "syndicat du Limpertsberg" is protesting against the fact that the tramway is going to corrupt their very nice neighbourhood. They were not consulted, and they call it "an invasion".
At the same time, at http://service.vdl.lu/forum/read.php?4,4102,4103#msg-4103 (the City of Luxembourg online forum) someone is asking for a direct bus line between Limpertsberg and Kirchberg. Others demand for more peripheral direct connections (meaning: if you don't live near Centre Hammilius or the Gare, chances are that you'll have to take two different buses to go anywhere).
Me, I've never been to the Limpertsberg village. I'm a city guy and I fell sick in deserted open spaces, full of cows and ticks, but I do believe that if people have chosen to live in the countryside, away from the turbulent city centre, they should be respected.
More posts about the tramway here.