Any advancement in commercial storage is big news 'round here so we're stoked to learn of a new ultra-thin hard disk from Seagate meant to slake our jones for super-slim portable computing. Seems that Seagate's already sampling a 7-mm high disk as part of its Momentus Thin series of drives scheduled to be launched at CES in January. Impressive, especially when you consider that just about every 2.5-inch SATA disk we cover measures in at 9.5-mm high. Although Seagate doesn't give specifics, we assume the drive will be spinning a single platter. And knowing that dual-platter 2.5-inch disks currently max out at 640GB (or 320GB per platter), we expect Seagate to at least match that single-platter capacity, but probably improve upon it via a boost in areal density. Feel free to offer your guess in comments until all is revealed on January 5th.