Turns out sometimes we get things right.
Sony Japan has confirmed this morning that it has ceased production of the digital-only handheld, adding to AV Watch that it is to "concentrate on NGP" going forwards. We imagine all those factories that were previously producing PSPgo systems, are now preparing for the NGP.
Sony was keen to add that the PSP-3000 will "continue to be sold, and we will keep focusing our attention on it from here on out". The PSP-3000 continues to be Japan's highest selling handheld, despite the release of the Nintendo 3DS.
It's a sad day to see the handheld so out of favour. We genuinely think the PSPgo is the best iteration of the PSP available. But we suppose the price and lack of legacy support made it a tough sell for many consumers.