BR drive or HDD? I ask as BR Drive won't matter as neither system will be playing games from the disc. HDD I'm sure will have to be 7200RPM at the least.

both preferrably, but are you positive about that not reading from disc thing?  So I'll still have to have the disc in but it will play a digital version?

It sounds like its one to one with the rumors of no used gaming. I'm betting that MSony have both devised (from pressure of publishers) to have a unique key-encoding per disc to be connected to a device/user. Once the game is installed the disc is only needed if you need to reinstall.

Otherwise, why force full install? I think it would be worthless to still require disc in drive if none of the assets from the disc are needed. Keep in mind all three companies are using bluray discs that have the meta-data areas on disc, even if Nintendo isn't allowing movie playback. 3rd parties could still use the same encoded keys on all 3 consoles, but of course Nintendo's wouldn't install the game, just track the key.

In this route, they could then enforce no used games as they see if that key has been registered upon installation from the disc.

that's just awful!  I don't wanna keep every game I ever buy!  I've bought many that once I platinumed I knew I would never go back to and haven't regretted dealing them away to pay for new ones.  I just hope there's an "uninstall" option so the disc can be used and you can sell it

PS4 games will run over the BD disc without need installs... only few game will use installs.

I really hope that is not the case. Having the game on the HDD is such a huge advantage for devs. It gives them much more memory bandwidth to play with. Reading from the disc is a massive bottleneck. I would hope that they could develope a way to install the game in the background to get rid of the wait to play, but I really hope they go the HDD route. 

RAM>SSD>HDD>BRD

http://www.neogaf.com/forum/showthread.php?t=530748

Info from GDC:

• Targeted to be the “central device in the living room”
• “Core gamers are our primary audience
• PS4 build around them, salable to the outsiders
• 5 core PS4 principles: Simple, Immediate, Social, Integrated, Personalized
• PS4 CPU: 64-bit x86 arch, low power consumption, low heat, 8 cores, 8 HW threads, 2MiB L2 cache per 4 core group, 32kib l1 I/D-cache
• PlayStation Shader Language, very similar to HLSL, allows featured BEYOND Direct X 11 and OpenGL 4.0
• “GPU – Tessellation – adding geometric detail to smooth edges or create more organic shapes”
• PS4 RAM – 8GB 256 bit GDDR5 (GDDR5 is very high end graphics memory only found on PC graphics cards)
• Will come with “very large hard drive in every console”
• PS4 Dev Environment – Windows 7-bit, tools are fully integrated into Visual Studio 2010 and 2012
• “Debug your PS4 code as you would your PC code”
• PS4 Controller: Start/Select buttons are now “Options.” New System button is “Share.”
• Speaker, headset hack and “extension port” on the PS4 controller
• PS4 controller buttons are going back to digital over analog because no one used it on PS3
• PS4 controller L2/R2 – Curved design to get rid of the accidental netflix fast forwarding
• PS4 controller: 1920×900 resolution on the analog touchpad
• PS4 controller colors are the Player Numbers: 1-Blue, 2-Red, 3-Green, 4-Pink (Like the buttons)
• PS4 will charge controllers when it’s off. Unlike the PS3.
• PS4 controller light bar can be used for muzzle flashes, health bars, etc
• “The #PS4 Eye will enhance the PS4 user experience.” High sensitivity dual color cameras
• 1280×800, 12 bits/pixel, 60Hz
• Dedicated port for the #PS4 camera, exclusive SCE Connector. Means it won’t use a USB port on the console, but won’t plug into your PC.
• Cam suggested uses: walkthrough vids, taunting in killcam, login, speech recognition, etc; possible PS4 Camera Magic – Sees the controller, you guys move, splitscreen moves to be on the right side
• The above is what devs could do (not mandatory)
• Video example shown of PS4 combining the camera and the controller. “AR Menu”
• Zoom into the controller, tilt to shake little dudes inside, push into our world like EyePet
• 2004: XMB, 2011: LiveArea, 2013: New #PS4 one based on the five principles from earlier
• UI is meant to give you at a glance info without loading the game. See what new DLC is out and whatnot. What friends are saying.
• Have to enable people seeing your real name on the #PS4. Auto-enabled if you import from another social network. (Can be turned off)
• PSN friend limit raised
• PS4 Mock-up: Heavy Rain choice with the number of your friends that chose each option.
• All the PS4 streaming and sharing: that’s on the hardware. Devs don’t have to do anything special to their game.
• PS4 Remote Play: Screens are mirrored on PS4/Vita (Both on at same time). Hardware does it/not on devs. Start at any time; no special mode.
• Talking about the PlayStation App. Login, buy game, PS4 starts downloading at home, you get home and start playing the part that’s DWLD.

Ok, updated various PS4 info based on details from GDC events today.

it seems like Microsoft and Sony are targeting living room, my consoles are all in my bedroom lol

They all want to be the central entertainment / smart device in the home. Made for full home not just kids bedroom.

I made a thread over a year ago that detailed this and how the OS services and smart features would be equally as important in the next-gen as the games would be. In essence, they are no longer "game consoles" and are instead "entertainment devices" with gaming just one of many services.

Nintendo is actually the only one keeping a gaming focus overall and I expect Apple and Google to stepup this year with a far larger gaming portion to their TV connected devices as well.