The design of that coin is not known yet, but the piece is already listed at the KNM website. There will be a "circulation" version of the silver coin which can be had at face value. (Other issues will be a silver €5 proof coin and a gold €10 proof coin, I suppose, but those will be more expensive.)
Also there seem to be plans to issue a commem dedicated to the "Afsluitdijk". That dam separates the North Sea (salt water) from the Ijsselmeer (now inland waters, partly polders) and connects Friesland and North Holland. The last gate in the dam was closed in May 1932, thus 75 years ago. http://www.rijkswaterstaat.nl/wateroverzic...ender/index.jsp
Not sure whether that will actually be a coin; the Dutch mint also makes quite a few commemorative medals. We will see.
(Edit: It's official now - there are no plans to issue an "Afsluitdijk" coin.)
Christian
