I finished the update to give premium members the ability to add custom texture packs.
It appears to work quite well. Here's the world from my let's play rendered with the Dokucraft HD texture pack.
Check it out here
You can upload any texture pack however I don't automatically add a world to the render queue after you upload the file. I wasn't sure if people would want to make other adjustments first so don't forget to check the "Render Again" checkbox if you want the world back in the queue.
Starting the update on the categories which will include "Premium" as one of the categories so you'll be able to view just the premium maps as well.
Any other ideas, this is a good time to be posting them since I have a little more free time to work on this.