Mega already accepts bitcoins and (hopefully) it isn't NSA controlled. Unlike Dropbox.
Thanks, but no thanks.
Sure, I wouldn't use DropBox to store aything I wouldn't trust to share with the NSA.
But from a "Global Bitcoin Acceptance" perspective, it would be GREAT if DropBox starts accepting Bitcoin.
Alternatively there's indeed Mega and Wuala, who encrypt your content client-side. Then it doesn't matter if it's NSA controlled or not (it probably is, even though they're both hosted outside evil corrupt human-rights-criminalizing countries such as China, the U.S. and North Korea).
By the way, you can also put a TrueCrypt volume in your DropBox folder. This way you effectively apply local encryption yourself. Whatever you store in the TrueCrypt volume, is backed up in your DropBox as well, yet 100% unaccessible for DropBox or the NSA or anyone.