You are right that the attacks have already started. Yesterday I had a friend ask me about an email she had received about Obama being a closet radical Muslim, complete with the charge that he attended a Madrassa. Christopher Hitchens has a post on Slate about Obama and his minister.
When Obama prattles on about changing the tone, reaching out, etc. he is implying that Democrats such as the Clintons, Gore, Kerry and Cleland got slimed because they were participating in this kind of mudslinging. This is hugely insulting.
I am sure the Swift Boat crowd will be so charmed by Obama that they will put down their knives and join hands with him to sing Kumbaya.