This has to be completely treated as a rumour for now, but Industry Gamers has claimed that "a reliable source" has stated the the NGP will have half the RAM originally slated, in order to lower the overall cost and compete with the price point of the 3DS.
It's also possible that the NGP will also no longer feature internal flash memory, and rely on external storage.
Early reports had suggested that the NGP would feature 512MB of RAM and 16GB of flash memory, but the rumour states that the cost of implementing those specs may push the RRP of the device above and beyond what Sony believe to be competitive. The 128MB of graphics memory remains but, if true, this could be a blow for those expecting more from the NGP from a technical standpoint.
It bears repeating that this is merely a rumour for now, but 01.net, where the rumour originated, is reportedly a reliable source when it comes to Sony info.
More news as we get it.