I live and work in The Netherlands and if there is a non-dutch speaker in one of my teams we default to English so everyone can follow the discussion, although it's a bit harder for everyone to follow and it takes a bit more time. For the younger people here English isn't a problem, for the 40+ (aged) people it can be. For even better adaption of English you should visit Scandinavia; In the short time I've been there I couldn't find a single person there that didn't speak decent English.
Default to English just because there is ONE person who doesn't understand? Come on. Be proud of your native tongue and speak it. This is how languages die. Are the dutch willing to have their language replaced with English in 50 years?
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.
If the foreigner is motivated enough he will learn Dutch anyway, in the meantime a common language is far more productive.
English is the business language of choice in most European countries. Also if you need to work with teams spread all over the world it is much easier.
I guess English will evolve too, there will be a lot more influence from other languages, caused by the internet.
I was recently in The Netherlands, and was surprised to find that the taxi drivers spoke better English than they do in Sydney.
(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!)