Data syncing is a huge problem and its need will only expand. Dropbox is at the forefront of this (i.e. when I think of search -> google, shopping -> amazon, online storage -> dropbox).

The consumer space is growing (more devices and users) and the enterprise space is wide open. I can see Dropbox going after Sharepoint et al.

You're right, it might not be enough to be the next google but they might come close.