...
Applications that want to “find devices on your local network” will pop up with an “Allow” or “Don’t Allow” dialog the first time any account logs into a computer. As of Beta 1, we do not have the ability to “Allow” these pop-ups silently.
Building a computer from scratch will show a “Welcome To Mac” screen before you can log in. As of Beta 1, we can not hide that screen.
Applications (a work in progress – not all Applications have been tested yet)
...