http://www.starwars.com/episode-iv/bts/article/f20070220/index.html
I'm really looking forward to this book. Looks like a truck load of rare pictures to be had, but the thing that bothers me from the previews is it seems to be heavy on images and light on text. Given the extensive archive mentioned in that starwars.com article, and that the original Making of Empire and Making of Jedi books are absolute goldmines of info, around 280 pages with maybe only a dozen pages of photos, I hope we're not going to be shortchanged on info here. There are already a glut of 'picturebook' style star wars books out there, I hope this doesn't become just another one. I like a bit of 'meat' to accompany my eyecandy, how ever pretty.
That said, the article mentions reworking the original Making of Empire and Jedi books into a similar format, and if they can do that without loosing text, those will be something to really look forward to. Also the hinted prospect of similar series of 'Making of Indiana Jones' books is potentially mouthwatering.