I have an SRTM-derived hillshade (30x30m) and a Quickbird scene (0.6x0.6m). Is it possible to kind of pan-sharp the hillshade to have the detail but also have the topography?
If you are trying to display the result you could simply layer the two data set on top of each other and change the transparency of the top layer.
If you are trying to do something more permanent you can use some raster arithmetic. I got some relatively good result by doing something like this for each band: "qb_scene@1" * ("shaded@1" / 255)