It doesn't mention harddrive specs because this is supposed to be a "cloud computer." However, it definitely has a harddrive and I wonder if it is a SSD or regular spinning disc drive.
Since ChromeOS is still pretty deficient at file management (even for picture uploading and such), I don't see any reason why they'd provide bigger hard drives unless they were intended to dual boot.
It also allows international travellers to have two of them, one at home and one abroad. They don't have to carry one through customs and subject it to an unreasonable search by border agents. For a small number of people this will be a good value. (I know it assumes you trust the Google cloud more than you trust DHS but that isn't too big of a stretch)
I used to sell thin clients that ran off of CompactFlash cards. (they ran a version of XP, too)