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.