Does the Ubuntu Server iso support full disk encryption out of the box?
If no, what options do I have to do this out of the box with a stock ISO now that alternate got nuked?
I have tried the Ubuntu 13.04 Server ISO. The installer does offer the option to create an Encrypted Volume.
I can't confirm that it works properly, since I am having some issues with grub2 and dual-booting.
EDIT: This answer offers working command line instructions for encrypting the filesystem root.