edit: Read it wrong.

Some titles use the checkerboard tech, some titles are native 4K, some titles are older titles with patches that improve things other than just resolution and some older titles won't get a patch at all.

It makes perfect sense writing it like that.

does the ps4 do 4k streaming??

I can't imagine there will be many, but yes, some games are native 4K. TLOUR for instance.

Just like some games on PS3 were 1080p. The ones that are fairly undemanding graphically, and run at 30fps.

Thank God that the consoles are getting AC.

Whats the source on this info? Can you verify that the PS4s actually has a HDMI 2.0 port?

And can someone please tell me what's the difference between BT 2 and BT 4? Or even better how it benefits the console?

I think its pretty much a given that every PS4 game with a Pro mode will run at 4k. Every single one. What kinda 4k that is though is another matter. My guess is that every AAA release will be  4Kc and majority of the indie titles will be 4K native. 

The PS4 is 1.8TF. Though I know it doesn't work like this but if say it were outputting two 1080p images it would need to at least be 3.6TF. The PS4 is 4.2TF, using my layman's example all it needs to render the 4M pixels it needs to render to do the checkerboard thing will be 3.6TF. Yes it doesn't really work this way but this example basically is a worst case scenario. 

it does, this is from Gaf so there you have it. 

As for BT, probably better range, less delay.