You can get by fine with English but to really feel at home - you should know the language. This is assuming you want to make the place you live in feel like home.
I was eventually able to pronounce Scheveningen, though.
Edit: All this is to say, of all the non-English-speaking countries to go to as an English speak, The Netherlands is probably the easiest to get by in.
All I'm saying is... if that one foreigner is motivated enough to stay in the Netherlands, he better damn well learn the language. He/she will have to anyway, in order to adapt in social settings.
I guess English will evolve too, there will be a lot more influence from other languages, caused by the internet.
(In Sydney a lot of taxis are driven by recent immigrants who's English is sometimes less-than-ideal, despite some kind of mandatory-English requirement. If they have a mandatory English requirement in The Netherlands for taxi drivers then the bar must be a lot higher than in Australia!)