Problem is: Sony didn't want to reply and clearify the official Ram amounts that are used for gaming or reserved by the OS.
If they had let's say 6GB for gaming and 2GB for the rest then they'd immidiately try to debunk this rumour because it created alot of heat in here.
Why should they openly admit something which got mainly recieved bad over the internt (or just gaf, dunno lol).
I say, and please don't hate me for it, that this statement is already a confirmation for this whole story (atleast when speaking of numbers).
Fact is: That 5GB are way enough to create awesome games. Can you imagine what future titles from Bethesda, Naughty Dog, Remedy, Crytek, CD Project, Bungie, Rockstar Games and so many more awesome game studios will look like?