In addition, the gripe I have about "channels" is that you lose track of who is wanting to run what. For instance: You go to the bathroom and all the sudden you missed that message that a healer was looking for your dungeon. I think a automated list that is consistently updated of players and what they are looking for makes it easier to track. But yea stay away from the automation of group formation and cross server stuff, kills community.
Also in addition undergeared people shouldn't be able to join with you so they ruin the fun and experience of the other guys. There should be minimum gear level for every dungeon as requirement so everybody can be prepared to fight in the certain dung.
Regards,
Shock! :)