but to be president he'll need a lot more national connections, fundraising prowess, etc.
Obama didn't have that built in. He obviously had to work for it and then there's the benefit of becoming the nominee. A nobody can become a somebody. Let's see how he builds himself if he wins in 2009.
True, but Obama had his DNC speech in 2004 to put himself on the radar. He'd been promoting himself through his book, which was not a typical politician's tome that no one reads, but something interesting. O'Donnell can't get that up and running in time for 2012. In addition, while O'Donnell's biography looks solid, there's nothing unique or interesting about him, nor is he particularly youthful although he's not old. He could be a solid candidate for 2016 if he does well as governor, and he also has potential for a supporting role in 2012, as others have said.
Being from Virginia does give him an automatic advantage for press awareness, though.