You know, I find it offensive when people speak of Senator Obama as an empty suit. Even if I was not a supporter those words would be offensive. An Empty Suit to me would be an individual with no accomplishments to speak of, no real life experience to speak of, no real challenges they've overcome, nothing that warrants examination but their presentation: their empty suit.
Looking at Obama's life story one can only be both amazed and impressed about what he's achieved so far. Harvard Law, Constitutional Law professor, Illinois senate, US Senate and no silver spoon in his crib either... It there was one it would have been a wooden spoon, actually.

If he was not running for president he would clearly be viewed as a successful American.
But if the implication is that he should be more "experienced" to run for President, it begs the question: what kind of expericence? And do the other candidates have it to not merit the "Empty Suit" label?
To my mind, nobody is really experienced enough to be President except for incumbents. So the question should not be "Is so-and-so experienced enough to be President?" it should be  "Has so-and-so's life experience prepared them for the challenges of the presidency?"
And clearly on that basis, a variety of life experiences would be deemed relevant, not only time spent in the halls of Congress or on the Senate floor.