Over on the Asimov's forum, editor Sheila Williams states that beginning with the December issue Asimov's will adopt a major redesign. To quote Williams, "The reason for the change is nothing to be alarmed by. Paper andproduction costs have presented [us] with a choice: increase subscription rates and single-issue costs to retain the old format, or adopt a slightly different size and return our current prices. The new size is called an L trim (5 7/8" x 8 5/8"). The page count will be reduced from 144 to 112. Since the new pages are larger than the old pages, the actual volume lost is about 8 pages or 4,000 words. I've made some minor changes that reduce any further word loss."
This change will also apply to the December issue of Asimov's sister magazine Analog. In case anyone is comparing the new size to the current size, the change means that Asimov's and Analog will be adding about a half inch to both their vertical and horizontal length.