Seems like our dear Guillaume has been quite busy giving interviews the last couple of weeks. On Friday a one hour long radio interview will be aired on Eldoradio. It will start at 3:50 p.m.
In the interview he talks about the obvious things like his opinion about monarchy; you can actually listen to him saying that in the link above.
Hereditary Grand Duke Guillaume also discloses the secret of having a girlfriend for over a year now. In case you had plans of becoming a Princess of Luxembourg yourself, don't be too worried as he also states Luxembourg will have to patient and wait a little longer for the fairytale wedding. And you wouldn't need to worry too much anyways as there are still Félix (well...) and Sébastien left. I can only recommend you to also have a look at all the hot cousins the three brothers have, becoming a Princess of Liechtenstein, Princess of Nassau or Archduchess of Austria certainly is nothing to sneeze at ;)