Is/was your friend an American citizen? I've been fascinated by emigrating to Europe for a long time and am always looking for stories about how people pull it off.
http://www.bamf.de/EN/Infothek/FragenAntworten/BlaueKarteEU/...
> Holders of an EU Blue Card can enter another Member State without a visa after 18 months and apply for the EU Blue Card of that Member State within a period of one month.
And it looks like Americans (at least for now...) can go to Germany before they're even approved:
> Exceptions apply to nationals of Australia, Canada, Israel, Japan, the Republic of Korea, New Zealand and the United States of America. They can enter Germany on a visa-free basis and can apply to the competent immigration authority in Germany for their future place of residence for an EU Blue Card within three months of entering Germany.
And while it's nice to learn the language and all, the NL has among the highest English competency in Europe. It's rather difficult to learn Dutch because English is so useful and prevalent.