Longer explanation can be found in Wikipedia under article <A HREF="http://en.wikipedia.org/wiki/Dissolution_of_the_Netherlands_Antilles">Dissoluti on of the Netherlands Antilles</A>.
Shortly, Curacao and Sint Maarten are now constituent countries under Kingdom of Netherlands. And Bonaire, Saba and Sint Eustatius are special municipalities of the Netherlands. But as TE classification is not and could never be so fine grained, I suggest that all those islands would be 'States' under Netherlands -> Other. BES islands don't have common governance, so I think they should not be grouped together. And for a normal tourist it is also more clear to show each island separately.