I can't help thinking the arguments put forward here are very similar to the ones put forward in the discussion of the Dutch Santa's little helper 'Black Pete'.

Black Pete : racism row

In that discussion defenders pull out the whole 'tradition, we've been doing it for ages, it's what we are' argument with a bit of 'PC gone mad' for added flavour. And while it may or may not be that the Saint's servant is a moorish pirate or not or whether there are racist overtones (in practice, there are, in the case of St Nicholas' assistant, IMHO)it doesn't really matter. People are offended and that should be reason enough to at least consider what the problem is and if anything can be done to make changes that form a comprise acceptable to all. Traditions are, after all, not set in stone.