The delegates are not locked in until the votes are cast at the convention. Unless some superpower in the Democrat party tells Hillary and Bill to pack up their dog and pony show in is inconceivable to me, just from reading books written about these two from way back, that she will go easily into that good night.
Can she win? Just as you say unless Obama has a complete meltdown, or (always hope) the American people turn off American Idol and Dance with the Stars to see what is going on around them, no. It will be Barak.
Another thing, Rush is taking credit with this "Operation Chaos" for keeping Hillary in this long. Maybe, I do not know for certain. But, I did hear someone today point out that it was the Democrats all along that keep this boxing match going. Why? So that all the voters see day after day is Clinton and Obama and they forget about McCain. By the time it is down to the Democrat or the Republican, many will have already decided for Obama. They see only McCain as a old man and do not even know a thing about him,or anything about what he went thru in Viet Nam. He says he will not bring it up for some reason or the other, however, I predict that there will be a "Swiftboat" in reverse where the ads will be all about his torture in Nam to get the Americans to see who he is. (That is if we know the real person behind any politician anywhere in the world).