Update – this is now part of the Outlook MAPI Code Samples.
I finally got around to testing the Wrapped PST sample with Outlook 2007 Beta 2. I found that I had hardcoded the path to mspst32.dll and it really didn't like that the path has changed in the beta. So I've gone in and hardcoded the new path in there as well. I'll leave the task of implementing a robust solution to anyone who wants to build a product out of this. :)
Anyway, that was the only change I had to make. Here's the updated code: http://stephengriffin.members.winisp.net/wrappst/wrappst.zip