The only way it happens if it he can keep producing for another 7-8 years, but that's not likely. His walks and HRs are awesome looking, but his batting average, terrible defense and sloth-like running skills take away so much of his value. Even saber-metric types aren't going to value him - Fangraphs has him as averaging less than 2.5 WAR a year - he's only got 25 WAR over 11 or 12 years. That isn't hall worthy. If he hangs out for 7-8 years and averages 30 HR, he could get to 600 HR. But that's a stretch. Guys like him to tend not to age well. Doesn't mean it won't happen, but even if he reaches 600 HR, he's going to have a sub-.250 BA. People will shake their heads at that. And they'll know he's been a DH/bad fielder all his career.