I realise probably only "power-users" would actually work with the XML, and in which case they may edit the XML in a text editor outside of the browser, but in-browser editing would be a nice feature which would be enhanced by syntax-highlighting, etc. The great (and open-source) Ace editor springs to mind.
While I'm at it, here is the rest of the "wish-list" - as far as I know, these are not current feature:
- Ability to upload/import Resources (say from CSV)
- Ability to manage Schedules/Monitors from within a Project (say "hold" a Scheduled Job until current Project task completes to prevent resource contention, etc.
- Sort Task - I have managed this to date by writing to a database table, sorting and re-reading.
- Reordering of columns in the table views in the UI - while it is possible to reorder columns in the Show/Hide Columns dialog, the reordering has no effect on the column display order)
- Variable substitution in Job Name (e.g. use a Project Variable value such as "Obtain file from Group ${groupID}"