Meat pies are similar to pot pies and traditionally come filled with meat and gravy. A key difference is that they tend to be hand pies (i.e. you pick them up and eat them with your hands rather than with a fork and/or knife).
The new pizza is called the Four'n Twenty Stuffed Crust pizza, after the brand that manufactures the pies. There are 8 meat pies per pizza and, apparently, they lift out of the crust quite easily. Squeezable packets of tomato sauce are included on the side.
You can see a video of Pizza Hut's Four'n Twenty Stuffed Crust pizza below:
Photos via Pizza Hut Australia.