I have recently created a description process on how to create signatures for Outlook, how to deploy them to many people at once, and for those users to be able to send from another mailbox. The article is now posted on the Exchange Team Blog Site with the actual link here. Sometimes the information we PFE’s build is specific enough for the team site. Other times our more general help with customer situations are just that, help and guidance for people to hopefully spend less time trying to troubleshoot an issue and to be more proactive in their environment.
There are several ways to use this signature option. Another way I've discovered is to have end users send out a default signature based on different options that they may need. I hope this information is of help to at least some of you.
I also want to thank Terrance Brennan who assisted me in tracking down some of the Outlook registry edits.