Another advantage is that a lot of european young people go to berlin, for example from france, U.K, holland, poland and so on. It's a city that draws the young upwardly mobile crowd, rather than the working class. So there is the sense of a diversity of ideas, and many different people doing different things. It's a city that does not feel very "german", it feels very european.
Berlin is not so great for people looking to work in the tech industry because there is no concentration of tech companies. But for self-starters, it's quite conducive.
I doubt that Berlin will really become the mecca for technology though, because I do not think it's easy to learn the german language, and in the end, Berlin is in Germany, and Germany is not very multi-cultural. London feels much free-er, English laws are much more conducive to small companies, and people already speak english.
Berlin imposes berlin on you, you have to kind of be the berlin type to like berlin, but I get the feeling, you can just be yourself in London.