So I finally squeezed in a little time to start reviewing the Alpha Rules. The proposed rules for clerics and turning caught my eye. There are two objectives identified: help offset the heal-bot archetype of the cleric class, and, I'm guessing, help offset some of the weird swinginess of the all-or-nothing turning we see in current 3.5 rules and streamline turning. I think the alpha rules are good starting point, but I think you could go a step further.
1) base channeling on d8
2) 1 die/level
3) no save
4) each time a cleric channels, they can distribute their d8s however they see fit to any creature within the burst radius (whatever that ends up being); positive against undead deals dice of damage, and for living heals that much damage ; vice versa for channeling negative energy
5) turn resistance negates one die for each point (average of d8 is approximately 5 points)
Alternatively, set resistance to positive energy at 5 points per point of turn resistance, giving cleric a chance to do some damage against even resistant undead (I was trying to eliminate substraction during combat and negating dice seemed more elegant).
If you really wanted to get fancy, you could set up some "die-equivalent" effects which could be added on to give clerics some tactical flexibility, such as "stunning," "fear,", etc. This would probably need to bring the save mechanism back in, so it might be an optional variant.