I just noticed on the IND website that after 1 October 2006 that the Naturalisation Ceremony is now mandatory in order to become a Dutch citizen. I think this is a good idea. After all, you should want to celebrate the event and make it an official kind of feeling. Otherwise maybe you shouldn’t be doing it. Here’s the official text:
The naturalisation ceremony on or after 1 October 2006
As of a fixed date in 2006, most probably 1 October 2006, it will be compulsory for you to attend the ceremony. Minors who were aged sixteen or seventeen at the time of the naturalisation request or option statement will also be required to attend. If you are invited for a ceremony taking place on or after this date, you will only become a Dutch national if you attend the ceremony. If you do not attend the ceremony, you will receive a new invitation for a future ceremony. You must attend a ceremony within one year of the decision being made; if you do not, you will not receive the Dutch nationality. Once the deadline has expired, you will need to begin a new naturalisation or option procedure if you still wish to become a Dutch national.