@irontoenail - A funeral might not be the best comparison though. In a funeral, people are grieving and maybe won't be willing to look on the brighter side of things. If you can't make allowances for kids in a wedding, which is a happy occasion, then you might have a problem.
On the other hand, it probably does depend a lot on the wedding. If you are being asked to travel for it, or if there is some other restriction, I would absolutely ask before taking my kids. Some weddings might only be catering for a very small, set number of people. But that's got more to do with wedding catering and venues than with kids per sec.