Like the other posters said - it's not a big deal unless the dewclaws stick out and are prone to catch on things. My manager's Chesapeake Bay Retriever tore one of his dewclaws at a field trial - it was one of the bloodiest injuries I've ever seen.

I'll always have the dewclaws on my dogs removed - simply because my dogs will be working dogs, and I'd be paranoid that they'd tear them on something.