Sony has confirmed that from October 24th people who use the Media Go app will no longer be able to access the PlayStation store from it. This will affect those who still use their PSPs to play games and watch videos. From October 17th those who own the E1000 model of the PSP, which doesn’t have Wi-Fi, will no longer be able to download and install purchase through Media Go, so Sony is advising that any content people want to download should do so by then.
This same situation does apply to other PSP models but since they have Wi-Fi, content will still be downloadable. Deactivation or activation of PSPs will not be achievable through the app from October 17th either, though can be done through account management. You will not be able to deactivate Media Go through PC for PlayStation Video playback though, and will have to contact Sony by email to get that done.
If PlayStation Video does remain active through Media Go on your PC you won’t be able to download titles you own but can stream them. That is applicable as long as you download and play them before the cutoff date, as from here you can stream titles.