On the box back of the new 4502 X-Wing Fighter, there is a small picture showing the Battle of Yavin with LEGO TIEs and X-Wings flying near a screen capture of the Death Star with "10131 01.08.2004" printed on it.
Could this be one of the two new exclusive Star Wars sets that will be released in August? A UCS Death Star would be a monster set. How could they get a good curved surface with square bricks? The LEGO spheres I've seen still retain a somewhat blocky shape even when smaller bricks are used.