Sony will continue to stock the PlayStation Network Store with the library of UMD games, which will be available for purchase on the NGP as well. Sony noted that while it's attempting to secure NGP card versions of UMD games, rights issues may prevent some games from coming to NGP at all. PSP Go owners have learned the hard lesson that not every game gets a digital version.
Sony declined to comment to Gigazine on whether users will have to re-buy their UMD existing collection, but says it's investigating possibilities. Then again, we have heard that before. Similar plans were scrapped for the North American PSP Go launch, though owners in Europe were able to use their UMDs to activate free PSN downloads.
We've reached out to Sony's North American division for clarification and will update with any response.