They are really nice but I really don't see the point why they are implemented in css. Most of the images make use of the capability of directly using gradients in the background-image property. Of course it could be easily replaced by the appropriate svg element.
For the lollypop shadow I would make use of the 3D transformation capabilities of CSS3. AFAIK svg is only capable of affine transformations (why?) while CSS3 can handle perspective transformations too.