I have always wondered why computer makers have so many different models/shapes/sizes etc. This building block system looks like a good solution that will probably be abandoned as soon as the paint drys. There is no point in re-imagining the computer case every year. We should be able to add/replace/delete etc various modules. A simple rectangular shape makes it easy to put on a shelf or in a cabinet.
As for it falling over...There are much thinner PC's on the market that don't tip over (anymore than the acer would). All about the size of an external DVD drive.
HP:
Acer:
Dell: