SurveyUSA has Clinton leading 52–43 (down from 56–39 a week ago). More interesting, though, are the crosstabs. SurveyUSA has devised a brilliant new way of slicing and dicing the electorate by age: among voters younger than he is, Obama leads 51–45. But he trails Clinton among voters older than he but younger than McCain (54–39), and is getting trounced among the tenth of voters older than McCain (69–24). Remarkably, Obama leads among all voters under the age of 50, and is still losing by nine points. That tells you something about the depth of Clinton's support among the Centrum Silver crowd. There's also, once again, an enormous gender gap (women: Clinton 62–34; men: Obama 55–39).
In addition, there's some strange geographic variation--Obama's winning by seven points in the Cincinnati area, but losing by a full 30 points in the Columbus area (this despite the fact that Cincinnati has only marginally more African-Americans than Columbus, and actually has more senior citizens too). In Cleveland and Dayton it's effectively tied, while Clinton's way ahead in Toledo and rural southeastern Ohio. Perhaps commenters with more knowledge of Ohio political demography than I have might shed some light on what's going on.