If you bought a new car and suddenly the dealership said, "oh, by the way, we've added a turbo charger for free," would you be angry?

My guess is that Sony wasn't sure if they'd go with the 8GB of RAM when they created the dev kits.  Better to have developers using 4GB and surprise them with 8GB than the other way around.

4GB of GDDR5 for OS ? 

I don't think so.

Apparently they kept it secret from microsoft as well.

That was reveled in February, no? Days after the presentation.

PS. I have absolute certain the guy that wrote the article knows nothing about hardware... the dev said GDDR5 and it wrote DDR5... DDR5 don't exists... if fact even the DDR4 is entering in the production phase soon (it was in development for years).

Read the OP.

An "added bonus" of PS4's memory is that Sony has "already ring-fenced the system memory away from the game memory," Gilray adds, "so there's none of this business that we had with PS3 of having to share memories.

"Yeah, 4GB, awesome, can't wait. But when they said 8GB it was like, 'Ooookay."

duh - even GG was surpised.

PS4 has a dedicated chip to handle the video recording features. This isn't going to take up any system resources.

Wii U is struggling with 1GB because Nintendo is Nintendo. The Wii U was rushed to market, which is ironic considering the console itself should have came out at least a year earlier.

Why would they be mad that the RAM was upgraded?

The reason 3rd parties weren't notified was because this was a recent decision on Sony's part. The PS4 reveal was used as a venue to make sure all 3rd parties knew THIS CONSOLE HAS 8GB OF GDDR5. Microsoft, your move. You either react to our specs, or suffer the humiliation of launching a weaker console.

That's because it wasn't always going to be 8GB. How is that news to anyone? Sony planned on 4GB and then later decided the cost to bump to 8GB was justified due to being comparable to what was rumored to be coming in neXtBox.

Sony's 8GB was as much a reactionary change as adding motion to the original PS3 controller. However, in this case it will actually benefit devs and gamers.

It bugs me when people don't know the difference between GDDR5 and DDR5, but act as if they are the same thing.