Tom Cruise and Katie Holmes did not put Oprah on their wedding invitation list. But she isn't losing sleep over the whole thing. I have a feeling it has something to do with the fact that Oprah didn't really defend Tom's couch antics. Here is what she said:
It's not that I'm not going. It's that they had a limited number of people that they could invite. I was not one of the invitees. That's fine. I don't get invited to everyone's wedding. I don't invite them to everything I do. But I wish them the best. I have a great deal of regard for their relationship and so I'm trying to think of what to get them." (source)