Asus is set to unveil an Eee PC 900 with a hard drive, the first such model in that particular family. According to a product sheet on the Asus Chinese site, the Eee PC 900 30G will come with 30GB of storage. Rather than using flash memory as in other Eee PC 900 models though, it will use a hard drive instead.
Other than that, the specifications are the same as those of other Eee PC 900 models. The site shows that battery life is down a bit from 2.5 hours to 2.2 hours though compared to the SSD models.
Linux configurations (in white or black) will sell for about USD$515 while Windows XP models (also available in either white or black) will sell for about USD$530. When and where the Eee PC 900 30G will be released has not been revealed yet (although China is a good bet).