For the record, Buffett supports Obama, and I mean big-time. http://news.muckety.com/2008/06/26/warren-buffett-does-doubleheader-to-raise-money-for-barack-obama/3702
I'm sure as a patriotic American Buffett would freely offer advice to McCain, but I rather doubt he would like the nature of the advice--e.g., raise taxes on higher income folks, obliterate the estate tax, etc. etc.
Prior to becoming the Goobernator of California, Ahnold asked for Buffett's advice and promptly rejected it. However, missus Ahnold supports Obama--testimony to a strong marriage IMHO. Cheers. Bob U.
P.S. We always have a great time when we visit the Republic of Texas where two of our children live.