Barry Bonds is now one homerun away from tying Hank Aaron's career record. While being a total classless prick for his entire career is justification enough for him to be booed mercilessly when he does tie and break the record, personality faults shouldn't be enough to keep one out of the record books (nor should they keep Pete Rose out of Cooperstown, but that's another debate). On the other hand, the undeniable tie between him and performance enhancing drugs through the BALCO scandal should be enough to at least see some note made in the record books alongside his record.
Several fellow high profile BALCO customers have since tested positive for, or admitted to obtaining and using performance enhancing drugs, including Marion Jones, Tim Montgomery and Jason Giambi. In addition are the claims laid by staff with the lab that Bonds did infact use. While obviously not guilty by association with those other people, it is pretty clear that Bonds used some form of performance enhancement during the prime of his homerun hitting career.
At this point nothing will keep him strictly out of the record books, particularly since an outright rule against steroid use doesn't appear to have existed in baseball rules at the time. However an asterisk, or an entirely separate column are justified both for his single season record (and possibly McGwire's 2nd place entry) and for the career total; "Career homeruns hit, assisted", "Most homeruns hit with use of performance enhancing drugs".
In the short term, the best I can hope for is that he continues swinging too hard at the ball through the weekend series at home, and then goes ahead and ties and breaks the record away where the fans will be more likely to give him the far less than positive reception he deserves, not only for his steroid use, but for the lack of class he has brought to ballparks and locker rooms throughout his career. Good on Bob Costas for not backing down after the way Bonds has regarded the media through the years, even better on the fans in LA or San Diego in the upcoming series' if they boo and heckle the hell out of him when the moment comes where he ties and surpasses the record.
Looking down the road, Alex Rodriguez is on pace to hit the 755 mark almost a full season faster than Barry, and he hasn't really hit the later career homerun hitting surge yet. While No-Rod has his own building collection of classlessness (take his bush league interference play in Toronto earlier this season), he still has time to atone for himself, and at least attempts to be media friendly in a city where the media is regarded as being the furthest from the same.