Over at TPM, Josh Marshall ponders whether there's any truth to this and concludes, reasonably, that there probably isn't. Being black has both helped and hurt Obama, just as being a women has both helped and hurt Hillary Clinton, but on balance it's pretty unlikely that Obama's color is a plus on his electoral ledger.
I'd just like to add one thing. Implicit in Ferraro's statement is the idea that if Obama were a charismatic young white guy, there's no way he'd be getting any attention. And that's just plain crackers. Charismatic young John F. Kennedy won the presidency in 1960. His brother, charismatic young Robert F. Kennedy, attracted huge support in 1968 and might have become president as well if he hadn't been assassinated. Charismatic young Gary Hart nearly stole the 1984 Democratic nomination from Walter Mondale. And charismatic young Bill Clinton won the presidency in 1992.
Being young and charismatic has been a pretty good combination in the Democratic Party for the past 50 years. And being against the Iraq war from the start is a pretty is a pretty strong credential in the Democratic Party this year. Contra Ferraro, if Obama were a white man he'd still be getting plenty of attention this year.