We encourage our users to enable AutoArchive in Outlook 2007 as a way to manage their mailbox sizes. However, we frequently end up running in to problems with the archive.pst file that is generated. The two main problems we have are:

1. The archive.pst file is located in the user's local profile directory and is never backed up. A dead hard drive or stolen laptop could result in months or years of missing email. All other personal data is stored on network shares, but we can't do that for Outlook PST files.
2. Without some sort of manual intervention, the archive will grow to enormous sizes. Although Outlook 2007 SP2 handles the large files better than before, it still results in slow response times from Outlook and an increase likelihood of a corrupt PST file.

To mitigate these problems personally, I move the archives to a c:\Outlook folder and manually back that up to a shared drive every month or so. Additionally, I rotate archive files every year so that I have one file for each year (archive2008.pst, etc).

Obviously, asking our users to do this same wouldn't help much. We need some sort of automated solution to take care of points 1 and 2.

I have to imagine this is a common problem for Exchange organizations, so what is the best method to handle this?