Installation root password is immediately marked expired
The installation process asks for a root password. Once the system is booted and running, any attempt to, for example, add new packages will silently fail (when using the GUI, which asks for the root password and then vanishes). It's not until you try to 'su' on a terminal window that you find out the just-supplied root password is now marked as expired, and you have to put in a new one.
While not major, this is annoying and quite confusing (since things fail with no messages) until you figure out what's going on.
This is on the 151a release image, 64-bit install.