If you want the friends and family you love around, off course the children should be there too. Children add to the wedding day and bring great fun of unpredicted actions and events. Providing children activities and using crèche service is a great idea if lots of children are coming. This is a small cost in the grand scheme of things and worth doing to ensure you have a perfect day.
Weddings can be unfair for children and can be a very formal event, and go on for hours. Unless a crèche service can be added it might be added work for parents and children. If you do not want children to attend your wedding, inform the parents on your guest list explaining your decision. This shows you are courteous and will avoid parents taking offence at your choice.
Where do you stand on this?