Well, Hillary Clinton really wasn't the only woman Obama could have chosen if he wanted a female running-mate. There are scores of women who are just as intelligent and politically savvy as Clinton has shown herself to be. So, if he was going to choose a woman, there's no reason why she should have been picked instead of some other woman. Furthermore, if spending time in the White House and being intelligent makes one more qualified than any other potential running-mate, we could just as well choose someone from the White House cooking or janitorial staff who has been working there through both Democratic and Republican presidencies. After all, they are experienced with what goes on there in ways that even Clinton might not be.
At the same time, I don't think that not being picked to be his running-mate will ruin Clinton's ability to run again. She's extremely intelligent and fairly young. Lots of people go on to run again even though they weren't nominated the first time they tried. I refuse to believe that she needs some man (e.g. Obama) to rescue her from failure. The idea that a woman should wait around to be picked by some man is as anti-feminist as I can imagine and it's certainly nothing that I'd hope Clinton would settle for. She has plenty of other things she can devote her talents to.
Furthermore, Clinton chose to put those millions of dollars into her campaign. The woman is a multi-millionaire. You don't get that kind of wealth without being financially savvy enough to know how much you can afford to invest in something where you could potentially lose it all. In other words, she obviously felt like the possibility of losing that money was worth the potential pay-off from her investment (i.e. winning the nomination and, eventually, the presidency). The money that she spent hasn't put a dent in the lifestyle that she enjoys. It hasn't bankrupted her or her family. And guess what? She's going to go on to make even more millions of dollars in the future. So, please people, stop getting all upset that Obama didn't rescue her from her debt, too.
This damsel-in-distress thing just becomes more clichéd every single day.