Looks nice, will be interesting to see how well it performs. I think it would be better to have thinner channels and more of them, but I'm sure that whatever you do will be far better than most air cooling systems.

What are you doing about getting the area where the block contacts the CPU smooth? It needs to be a very flat surface to work well.

I'm thinking of making one at some point. You can simulate the heat flow very nicely in solid works without too much effort. What socket is yours?