The new Smart Objects layers are a big improvement, though the implementation could use some refinement. On one hand, they allow you to apply filters nondestructively; Photoshop essentially associates a history stack of commands and parameters with the Smart Object, rendering them for screen display but not changing the underlying bitmap. You can always go back and edit the parameters for the filters. This method works very well for blur, sharpen, render effects and other independent filters. However, filters that are part of the Filter Gallery get lumped together, so that you can't, say, fade individual effects. That made sense for previous versions of Photoshop, but would work better individually with the Smart Objects implementation.