A question which is asked more and more often is how to export an archive back to the original mailbox (or PST) and remove the items from the archive in the process. It's quite straight forward to do inside the Export Archive wizard. The only thing to remember is that you have choose specific options, as shown below:
If you just choose the 'Export all Items' option, then unfortunately you don't get the option to remove the items from the archive itself. So to get around this you choose to export everything from root ('\') and you can then remove the items from the archive.