Latest news suggests that Sony are considering putting closed system software onto their PSP Go. This means you will be able to close the system up and still be able to use some games and applications.
Obviously closed system gameplay will only be possible for some games and you will have to launch the application or game before you shut the system.
It may be tricky to use this feature, as only the left and right bumper buttons are available when the system is shut. This will severely limit the number of games that can be played whilst the system is closed, but there is talk of a touch screen, which would make closed system gaming on the PSP Go a whole lot easier. However, the addition of a touchscreen is very unlikely at this stage, given that Sony have already given people a hands on demo of the new device at the E3 Expo.
PSP Go closed system, closed system software, PSP Go closed