Hmmm I did say that it's probably not the PSP2, but now I'm thinking why would Sony make two devices? Then I thought, this is kind of like the iPhone vs iPod touch question. So who knows...
Having 3G would make mobile online gaming much easier and if it works well, the dual analog touchpad could be a very cool innovation. Sony actually seems to be moving in the right direction with their devices, so color me impressed.
Edit: @Bdog
The article says that it will have a special Sony Marketplace for games, so other Android devices won't have access to the games, also I imagine without the slide-out controls it would be difficult to play most games on other devices.
Edit2: I just went back and checked Engadget's article from earlier when they first caught wind of this device, and apparently it is looking to be a first of many, and not all SonyEricsson 'Playstation Phones'. Rather, this phone is to be the first step in improving gaming on Android phones. There will be a special marektplace, but only phones with a similar control configuration will have access to it.