Well, ladies and gentlemen. Great news. The Hauck has found some dialogs that we've been looking for in ages so I'm putting this tutorial together to relay all the info to you wonderful login creators.
Let's start with Winlogon.exe. Open this up in Reshacker and you'll see a few sections on the right hand side. Feel free to edit the dialogs section (the text you will find in quotes) but be aware you will only see this if you have your system set to Windows 2000 mode (i.e. you don't use visual styles).
Under String Table, here are the most relevant items to change (though feel free to browse around and change any other text in here you wish).
96->1033
--1526 : It is now safe to turn of your computer.
105->1033
--1675 : Preparing Network Connections...
--1676 : Applying Computer Settings...
--1679 : Applying Personal Settings...
106->1033
--1682 : Loading your personal settings...
--1684 : Windows is shutting down...
--1685 : Preparing to stand By...
--1686 : Preparing to Hibernate...
--1687 : Saving your settings...
--1690 : Windows is starting up...
--1691 : Logging off...
110->1033
--1758 : Shutting down your computer...
As I stated earlier, there are many more strings in here you may wish to change...just take a look around and see what you find.
Now, in msgina.dll:
94->1033
--1503 : Your Password will expire in %d days. Do you want to change it now?
95->1033
(Lots of password dialogs...I won't list them all)
96->1033
--1520 : Restart System (mouseover dialog in start menu)
--1527 : Shutdown Message (mouseover dialog in start menu)
101->1033
--1606 : Log Off Windows (mouseover dialog in start menu)
501->1033
(Lots of shutdown, restart, log off, and hibernate messages)
Once again....there are LOTS of other messages in here that you may want to customize. Just change any of the text that you desire.
And lastly, user32.dll:
45->1033
712-714: Warning messages if shutting down while other users are logged in
I shouldn't need to tell you by now that there other strings in here you may wish to edit.
I hope this helps all of you who have been looking for these strings for so long. So long!