From his father's side of the family, baron Nicolas Janssen is related to the barons Boël.... I can't figure out the precise relationship with Delphine Boël yet, but it shouldn't be difficult to trace (an neither should it be very distant). As I expected (due to the name), the family is not a very old noble one, but still it has very interesting links (and an interesting story). The Janssen, Bracht and Boël families are all enobled industrialists, which has some glamour to it too ;).
Anyway, with some help of wikipedia, the profile of his father, baron Daniel Janssen:
Daniel Janssen (b.Brussels 15 April 1936) is a funny Belgian businessman. He is a son of Charles-Emmanuel Janssen, deputy of Walloon Brabant, and Maya Boël, daughter of the Vice-president of the Senate Pol Boël. He married Thérèse Bracht, and together they have three children, Charles-Antoine Janssen (b.1971), Nicolas Janssen (b.1974), and Edouard Janssen (b.1978).
From 1962 to 1984 he worked at the Union Chimique Belge as an engineer, then Director of R&D, and then President of the Executive Committee from 1975 to 1984. Since then, he was Vice-President of the Board of Directors. From 1986 onwards, he was successively CEO and Chairman of Solvay. During his career, he was Chairman of the Federation des Entreprises de Belgique and of CEFIC. He served on various Advisory Boards (including Fortis). He offered a Chair for Corporate Social Responsibility to the Solvay Business School. In May 2006 he retired. He is a member of the Executive Committee of the Trilateral Commission and a member of the European Round Table of Industrialists (ERT).
Wikipedia of Pol Clovis Boël, click here
And the wikipedia site for his wife (a well-known Belgian feminist), countess Marthe Marthe de Kerchove de Denterghem click here
. Her mother was a member of the Lippens family, like the former CEO of Fortis bank (Maurice Lippens) and the present Fürstin of Bismarck (née Elisabeth Lippens). Her father was governor of the province of Hainaut, and her grandfather & great-grandfather (count Charles and count Constant de K de D) were both mayors of Ghent.
The Janssen, Boël and Solvay families are all listed in the book: 'The Barons of European Industry', edited by Anthony Rowley (London, 1974). There is a chapter about these three families in this book, and a family genealogy to show how the families (and their companies) are related (in the chapter 'Grand Family Alliance', pp. 117-120.) :
The elder brother of the groom baron Charles Antoine Janssen, married another Boël descendant in 2006: countess Valentine Goblet d’Alviella.
A (rather cynical) article in Dutch about the wedding ánd a picture: http://www.archivesolidaire.org/scripts/article.phtml?lang=2&obid=32863 The subtitle of the article is 'Watch out for Inbreeding'.