Will that work with the Dropbox clients on my Android phone, my Android tablet, my Windows desktop, my OSX laptop and my Linux server? If not, then it's no use to me.
It works well for me (primarily linux, also Windows in a linux-hosted VM with dropbox served locally via samba). ecryptfs is standard on Debian and Ubuntu (very likely Redhat as they develop it). I have noticed some efforts to get ecryptfs running on the sdcard/data partitions in Android, but I haven't tried them yet. I haven't used Dropbox on Android since I learned their mobile client doesn't use https. As far as OSX goes, I don't know and I'm unlikely to care.
The Android and iOS mobile clients don't currently use HTTPS for transferring meta-data, but do for file contents.
ecryptfs isn't a suitable alternative to my suggested solution which would involve all Dropbox clients having the capability built in. Of course, people who are really paranoid can use their own layer of encryption on top as well/instead.
Fair enough, but having something built in to Dropbox for people who value convenience wouldn't prevent anyone from using solutions like ecryptfs as well.
