TVNZ has a video report on the launch of Kim Dotcom’s Mega 2.0 on the anniversary of that raid.
The report includes Clive Elliott‘s view on the copyright significance of the encryption arrangements. Unlike Dropbox et al., only the user/uploader has the encryption keys for the files they upload.
As Clive pointed out, there are already players in the user-encrypted field: e.g. SpiderOak, Wuala (which don’t come with quite the same notoriety, but do have their own challenges from a user’s point of view).
The new user encryption arrangements, however, may well not save Mega 2.0 if there is other evidence of Mega 2.0 employees inciting or being involved in infringing activity: cf. e.g. Roadshow at  or Kazaa.