We have the same problem that many companies do: We use Exchange, but we also use PST's for archiving. We're a small site, and don't currently want a full Exchange archiving solution, so using Outlook's archival abilities is great.
However, we now need to worry about backing up those PSTs. We don't backup desktops however, so this presents a problem.
How is this generally handled?
Should we setup a GPO that replicates this data to a network share?
One problem with this approach is that you need a local cache version, and copying a huge PST every logon/logoff could present a problem.