I don't think it was ever in doubt that that pic was a fake was it? There are some box art shots etc from some of the trade shows featuring some of the "lost" items (mainly the mp3 player iirc) - searching the forums should yield those...
As for the unreleased games? I doubt whether we'll ever see them. I've been following the dev groups for years now and still haven't seen *anything* out of the official teams.
It's extremely unlikely that any (bar the one Aruze pachinko game which *nearly* made production) of the unreleased games ever made it to the cartridge duplication stage - the NGPC development kit consisted of the various compilers (actually, SNK only officially supported the assembler - the standard toshiba C compiler was used if developers needed C, but I don't think there was ever an official SNK C library) an emulator (possibly hardware assisted). I'm not even sure if there was a flash linker kit, although I would have thought that there was. But anyway, cartridges would only be produced when the game was going to production.
It's possible that playmore or, more likely, the original development teams have some of the source/ROM images/graphics hanging around on disk or in their warehouses but they have repeatedly stated that they have zero interest in releasing NGPC stuff. Shame on them.
Cheers
Chris