I understand what you are getting at, but the question is not quite right. Nobody wants a smaller *sensor* - but everybody wants a smaller camera + lens.
Actually, a camera can be too small. Below a certain size, ergonomic complications start to set in, especially if the camera has a lot of physical controls (dials and knobs).
But can a camera be too *light*? (Or a woman too thin, or a man too rich?) I think not.
Some say a smaller, lighter camera feels unbalanced when mounted to a big heavy zoom, but I say the problem is not that the camera is too light, but that the zoom is too heavy.
So, I want what everyone wants - the biggest possible sensor in the lightest possible camera body which is small enough to carry, but not too small to operate. And we will want some lenses to go with that, too - the small lightweight ones, with the enormous maximum apertures, and real metal, too; none of that plastic crap.