I think we can definitively put the "he was just some guy in my neighborhood explanation" behind us. Noted racist right wing organization CNN has a report on the relationship between Obama and William Ayers and they found "the relationship between Obama and Ayers went much deeper, ran much longer, and was much more political than Obama said." Here is the video:

For the details on Ayers and Obama see the indispensable Stanley Kurtz here and here and here.