After having success with implementing wildcard search with MOSS, I decided to look into this whether or not I could inherit from the PeopleCoreResultsWebPart today to implement wildcard search functionality and unfortunately I did not get very far.  The issue is that the class is sealed.  This means that I can't just simply inherit from it and change the method that sets the query.  I now understand that the only reason CoreResultsWebPart is not marked sealed (its the only search web part that isn't) is because it had to be left unsealed so that the People Search web part could inherit from it.  I can probably do some more hacking by creating my own web part and using some reflection to load the PeopleCoreResultsWebPart and change what I need to, but that is going to take some time.  In the meantime, you can always use the WildcardSearchCoreResultsWebPart (but of course you give up all of the fancy PeopleCoreResultsWebPart functionality) or you can make use of Ramon Scott's handy JavaScript.