Yeah from the Japanese docs I've seen, with my Self Tought Japanese I learned, and jap gf the best I could read, is that the Slim PS3 was done
#1. It reduces the size of the shipping box, meaning Sony can pack more in to air plane cargo shipments, and cargo boat.
#2. It reduces the Weight, as we know Shipping from China to California is based on Weight Both in Cargo boat, or Cargo air plane, so it reduces weight saves Sony money and they can pack more units in.
#3. Its the PS3 Slim because Sony has now made the Power supply External thereby saving weight and Size.
Plus right now because of the PS3 size and weight It costs Sony, roughly $30+ to Ship a PS3 back and forth for repair reasons
By making a smaller light PS3, it can go down to $15. If you have ever shipped anything you know this.
#4. No WiFi, for gaming, I only trust Wired, and it saves Sony about $10 per Console leaving out the WiFi Chip
I could care less, as Long as Its $299 I am in