Inside the Sony Ericsson PlayStation phone will be a 1GHz Qualcomm CPU, 512 MB of RAM, 1GB ROM and a microSD card slot. The touchscreen size isn't confirmed just yet but it's said to be between 3.7" and 4.1"(which sounds pretty reasonable for a gaming device). Oh, and you'll be getting a multitouch pad on the lower half of the slider for a complete gaming experience.
The pricing of the device is still unknown, but that's to be expected with the device not even officially announced yet. Considering that the latest Google OS isn't even officially announced yet, chances are you won't be able to get yourselves one of those babies for Christmas.