I know a couple who have a wolf or wolf-cross. Wolf-crosses are almost always dangerous because, I suspect, they're really quite confused as to being a wolf, or a dog; and people who have them tend not to be aware that they're not going to behave quite like a dog. Wolves are not tame, and cannot be tame - at most they can work out accomodations with people if caught extremely young.

This particular wolf / wolf-cross worked out well for the couple I know. When they realized what they probably had - they never got a pedigree on the animal - they did not treat it like a normal pet, but instead read up on wolves. It also helps that they have a large amount of fenced land for the animal to roam on, and that she is usually outdoors. They also made sure that this wolf knew that one of the people in this couple was Alpha. At this point, she's old and arthritic, and may not have more than a year or two left in her.

However, this may be an exception, even with people willing to go the extra mile to understand their animal. Often, the cross brings out the worst in both species. (Or maybe their animal really is a pureblood wolf!)