I was guessing that the building in the upper portion of the image was the Wales Millennium Centre, as it was the only building in the area to have the correct curve in the front. But it didn't seem right to me.
A helpful reader named Jamble popped by to say:
These satellite images are well out of date, the Wales Millennium Centre is on that patch of bare ground below the large building - which is the Red Dragon centre, home to the Doctor Who exhibition.Well, that clears that up.
More Torchwood locations can be found via www.visitcardiff.com/torchwood.html
I took a poke around the Visit Cardiff site, and they have a nice little Google maps interface with a fair number of Torchwood locations, including one of the buildings that Captain Jack stands on to sulk! They put it here:
If my memory serves me correctly, he was standing on the beam on the right side of the building in the lower left, but the marker is pointed at a different building. Is the real building another one that wasn't built when the satellite went past?
Oh Google Maps, you are a harsh mistress.