Per this CNet article, Toshiba announced 10gig and 20gig versions of it's 1.8" drives... the 5gig version being used in the current Apple iPod:
Toshiba said it would begin shipping the 10GB drive, dubbed the MK1003GAL, in February and the 20GB unit, known as the MK2003GAH, in March. The company did not announce pricing for the new drives.