As someone pointed out in the comments these processors require DDR3 memory, which is only available (currently) in BGA packages. This means you can't quite use a soldering iron to build your own small computer, yet.

The real advantage here is not the savings in the soldering soldering but the savings in PCB complexity and cost. A small BGA with a few hundred pins will need at least 6 or more layers to be able to "break-out" all the pins from underneath the chip. With the TQFP package, all the pins are already at the edge of the chip, so it's possible to use a 4 layer PCB.

It's an exciting time when more people can have access build thing using this level of hardware. Now the next thing we need is decent documentation to go with these chips.