The latest image is of the Rosette Nebula, a region of high mass star formation in our own galaxy, about 500 light years away. The colours indicate dust temperature, ranging from 10K (red) to 50K (blue). The bright blobs are where high mass stars, 10 times as massive as our Sun or more, are forming. You can read more about this image at the ESA Herschel pages.
Much more will be coming out of Herschel at the start of May when the first scientific results conference is held at ESTEC in the Netherlands.