It's kind of funny how "tram" (Straßenbahn) is considered old-fashioned over here, while "light rail" (Stadtbahn) is all modern and convenient... basically the same thing, but the new word makes it seem more fashionable to politicians or something.
At any rate, Hamburg is apparently going to get a light rail system; I just recently heard about the web site the HOCHBAHN set up about it in the HVV (local public transport association) email newsletter, though the site has been up since October and the decision to get one was, apparently, in January.
So, depending on how quickly the planning goes, we might have
trams running from Bramfeld to U-Kellinghusenstraße in 2014, with an extension of the line to Altona, as well as further lines, possible in the future.
So, we shall see.
When I mentioned that to a colleague, he said that was a stupid idea, especially given that the first line would be along a stretch already served by busses. I mentioned that one of the plans was to run a line along the route of the 5 (ex-102, ex-tram line 2), which is (according to the web site) the most heavily-used bus line in Europe, where they need to run doubly-articulated busses to handle the traffic, and he said, well, a light rail train with 200 seats won't have any advantage compared to a bus with 200 seats.
I don't know whether the busses even seat as many as a light rail train, to which he replied, well they can just chuck a couple of dozen more busses at the problem to handle the traffic then, have them running every couple of minutes—it'd still be cheaper than laying tracks and laying overhead lines for electricity and building a new depot and maintaining the lot.
I have no idea, but I presume that the people who decided for a light rail system (as opposed to another underground line or busses) crunched the numbers and arrived at the decision for decent reasons... rather than just because they want a light rail system.
Eh. It's going to happen anyway.