Sharing Outlook mail rules
In Tools|Rules and Alerts...
, click the Options
button on the RHS. There's an Export
button on that dialog that allows you to export your rules.
I agree that this is a deficiency in Outlook. It looks like not much has changed as of outlook.exe version 15.0.4711.1003.
There's a 3rd party plug-in called "Power Rules Manager" by Sperry Software that appears to, among other things, allow import/export to an editable XML format. I haven't used this tool myself since it appears that it would require a separate license for every user that wanted to either create or use share-able rules.