As was said earlier, clouds are shallow 3d polygon "pyramids". They look great face-on, but when flying through them or past them, you'll see the shallowness of the object. I'd love to see true volumetric clouds, but that would be a great strain on mid and low range computers - something HTC will probably not choose to do...hopefully will show up some day as an option that those of us with higher-end computers could activate.