15 mins at 1080P eats up a lot of space, but then the PS4 should be streaming that to the HDD.  The Hibernate feature is something that could also be streamed to the HDD or kept in memory or a combination of both.  

What I think is that Sony has a lot of non gaming features they have not talke about yet.  All the features the PS4 will do for games and non games will need just as much memory as the X1.  The difference is that MS hard coded this value at the start and Sony is trying to figure out what they need once things get settled.  I am sure Sony does not want a situation where they do not have enough memory to do something like cross game chat which ended up being a feature the 360 coudl do but the PS3 could not due to memory.

As myself and others around the internet have pointed out, we've been getting games like Grand Theft Auto 4, Halo 4, and The Last of Us on machines that only have half a gig of RAM in total. The truth is, 7 gigs of RAM for gaming was overkill depending on who you asked. People often try to make point-for-point comparisons between PCs and consoles and it just doesn't work because consoles are highly customized and built from the ground up to run games. So when PC games are recommending 4 gigs of RAM people are getting the wrong idea thinking that the same requirements would be made of consoles. A lot of fanboys were running their mouths about 7 gigs of RAM for gaming without really realizing that not only would that amount make little to no difference against the Xbox One but that by the time it did, the generation would pretty much be over and it wouldn't matter anymore. I was honestly surprised Sony was devoting that much to games but I just let it go because I figured they knew something I didn't. The more I thought about it though the more I came to wonder why it seemed like Sony was devoting such a tremendous amount of fast RAM to games. It was like they were trying to highly future proof the system while forgetting that both consoles would already be hitting bottlenecks thanks to their GPUs and CPUs long before even having just 5 gigs of RAM for games became an issue. If they were that kind of serious about future proofing they should have also gone for better overall specs than they have.

As far as the rumor about Xbox One going for more RAM, I can tell you with confidence to forget about it. It really wouldn't be in Microsoft's best interest to delay production just to change everything up so they can jam a ton more RAM into the console. It would be the same problem. It would be WAY too much RAM that wouldn't make any sense at all because developers would get nowhere near using that much RAM before it was time for the new generation. It really would be an incredible waste of time, money, and resources. If Microsoft was going to make any kind of change to the specs it would be more likely that they'd go for a more powerful GPU or CPU. Even that's not going to happen at this point. Such changes would be way too drastic and Microsoft would probably have to delay the console until late next year. Seeing as how many indications have them being behind already, that would be a very bad move.

Lot's of porn multi-tasking. 

Maybe I am little bit to hardcore. But in all honesty I would have preferred all the specs to be improved especially RAM, processor speed, and HD. I find 500 GB HD a little bit to small when you consider the size of the games will only increase and with services like PS plus taking so much space. Only reason I prefer more RAM then 8gb is because looking at it right now 512mb of ram is just plain to small. I have a computer with 8gb of ram and it has been plenty for anything I have wanted and probably will still be good for years but I will probably upgrade in the next 3 years.