Add my hat to the ring (if there's still room).
Here are a few ideas for characters:
Kalashtar Psion: This Kalashtar has a lot of problems. His symbiosis was incomplete or damaged, and as a result he is living on two planes simultaneously on Eberron and Dal Quor. He is an incredibly powerful psion, but his dislocation causes him to often ramble on in incomprehensible languages and hold conversations with beings who aren't there, and in general not have very much control over his abilities. An additional problem is created in that his psionic abilities give him the power to recreate the world around him in the image of Dal Quor. On top of that, he is being hunted by his former extra-dimensional slave-masters who want their favorite pet back. His journey could be learning how to seperate his two realities, and function like a normal kalashtar, and being more accepted by society, while finally putting an end to his former captors.
Hive-mind insect swarm gestalt barbarian-rogue: OK, this is a bit of a sick one, and I haven't worked out the mechanics of it. The character is actually the hive mind of a swarm creature of some kind, with the ability to take humanoid form (writhing statue of maggots, anyone). He/she/it was the experiment of a mad wizard, whom I later accidentally killed (or was it accidental?) He/she/it is drivin by instinct and the need for survival, but has started to become intrigued with humanoids and their strange behaviors (emotions, nations, etc...). He has the ability to change into his swarm shape at will, which gives him great rogue-ish abilities, and he also gets agitated easily (hence the barbarian).
Radiant Idol (no character class): Elessa is an angel that has been banished from Syrania and condemned to spend enternity on the Material Plane. Her crime was that of trying to impart forbidden knowledge to the inhabitants of Eberron. She is obsessed with being worshipped by mortals and is secretly using the group as a way to increase her flock. Her ultimate desire is to return to Syrania, but she realizes that this will probably take her at least a few milennia. In the meantime she is interested in finding distractions and keeping herself entertained in this drab, dull world.
Ooh, ooh, one more. Human. Barbarian/Reaping Mauler: Directly stolen from the upcoming Jet Li movie "Unleashed", this half-orc was raised by humans as basically a dog in a cage. He has no understanding of culture and behavior, and has been trained only to kill and protect his master. He is calm and controllable when he is wearing his collar. When someone takes it off (he can't take it off himself yet) he kills, and kills extremely efficiently. He has no morals, ethics or inhibitions. His journey is learning who he really is and becoming fully human and trusting the people around him who care about him and want him to grow.
Let me know what you think. As I don't have the ECS book with me at the moment, I can't make them any more specific at the moment.
)
Some great ideas. 
