Think you know everything there is to know about the Next Generation Portable's capabilities? Not quite.
When Sony announced their sleek new handheld, they said that certain downloadable PSP games could be re-downloaded to the NGP when it arrived. But they didn't mention anything about backwards compatibility; most have assumed it won't be possible, as the NGP won't support UMD. However, according to Andriasang citing Japanese blog Gigazine, Sony has said they do plan to re-release select PSP UMD titles on the NGP's flash-based data cards. At the same time, rights issues may prevent some games from making the leap, so don't think you'll be able to replace your entire PSP collection. As for those with big UMD libraries, Sony is currently seeking possible solutions; all they'll say is more PSP titles will be launched on the PlayStation Store. That, of course, is a way of making such games available on multiple devices.
You may remember that this was a topic of discussion regarding the UMD-less PSP Go but despite similar hopes by Sony, they never offered UMD transfers or some sort of voucher system. Right now, there are no plans to present handheld fans with a UMD reader device for the NGP, but there is one important difference between the NGP and the PSP Go: Sony has long since admitted the latter was more of an experiment than anything else; a way of gauging consumer's interest and level of "acceptedness" in certain elements of portable entertainment.
Therefore, they may indeed find a way to make the transition from the PSP to the NGP a less painful one for handheld aficionados. We'll have to wait and see.