This is my conundrum. That bookshelf looks precarious as fuck! I haven't pulled the trigger on buying one yet for this concern. I'm thinking about moving to a new place soon though... probably one of the requirements will be room enough for a 60" bookshelf
I know it looks high, but Ikea has engineered the bookshelf so that it starts to lean back against the wall the more stuff you put on it. Unless someone comes and tries to push stuff off the shelve or knock the whole thing over, it won't go anywhere. Now when little children enter the picture, that's a different story. =P