They aren't the first to have a 640GB notebook drive, with Western Digital beating them to the punch by several months. Both drives have comparable specifications, so there's nothing spectacular about Seagate's release. We can expect the Momentus 5400.7 to sell for around $120, comparable to the Western Digital Blue Scorpio.
These two vendors are now the only ones to offer 640GB 2.5" drives. Will others move in as well, or instead reach for the loftier goal of 1TB? As demand increases for higher-capacity SSDs, we must wonder if SSDs or traditional disks will be the R&D priority for this year.