I totally agree. That's why 2012 would be the last shot she'd take. In 2016, she'll be 4 more years removed (and older). She'll be the Rat John McCain.
If 2008 was Hillary's last, best shot, how does it follow that she'll try again in 2012? She had her chance, and she lost. It's over for her, for all of the reasons I laid out.
Now, she might launch an exploratory campaign, just to see what her odds for 2012 look like. I'd say that's a possibility. However, events would have to align perfectly for her to have a real second chance. It's very hard to see that happening, given the trajectory of events now.