I've got all the plumbing complete, plus an electrical run out to where the island is going to be. I back filled the trench and have everything tamped down. The plumbing has been pressure tested too and am confident there are no leaks.
I am not sure if I really needed to do this out not, but usual TJ fashion, I want make sure everything is extra strong, so in order to make sure the new poured concrete doesn't heave or settle, I drilled half inch holes in the side the trench and epoxied rebar into the holes. That should hold it! (Concrete doesn't necessarily stick together unless you use a bonding agent or pin it like I did).
Now the fun begins!!! 10 bags of 80 lb concrete / mixed in the wheel barrow.
I used a straight finishing trowel for the finish.