I think professions is something that shoulod have been added to DDO a long time ago and definately think it is something that needs to be seriously considered for a future update.
Professions is something that many players enjoy and where some very unique items could be made. It might even open up some nice new shops ideas for the developers to work on in the current game both in Forgotten Realms and Eberron. Those old vendor shops that now just have a general vendor in it could be the brokers/professions AH point of contact. There could also be blacksmith shops and other themed vendor/AH points.
Some professions to consider:
Sage (potion maker)
All player crafted items would have some unique looks, colors, abilities, etc. They do not have to be super uber items but as a professions level goes up it would unlock more and more items and complexities.