I had an idea: Incarnum for 4e. My first thought was you would have "daily" soulmelds, which you can shape after an extended rest, and give you access to benefits throughout the day. Encounter soulmelds would be effects triggered once by the power then by at-wills. For example, you could have an encounter power that allowed you to attack vs. AC for 1d6+CON mod. damage and the ability to repeat the same attack through at-wills (obviously, the power would do more than that) for the rest of the encounter. Essentia would be a common trait, but each class would use it differently. For the striker class, you could use it to get more damage.

So, does anybody else have any ideas?