Jack Tretton, SCEA’s CEO has assaulted his two major competitors, Nintendo and Microsoft, in an interview he gave to Fortune today.

Tretton seemed confident and told that the PS3 is “just hitting its stride” with the console’s hardware, as things are falling in place for them.

In another rather blunt statement, he remarked about both the Xbox 360 and Wii, saying: “They’re starting to run out of steam now in terms of continuing to be relevant in 2011 and beyond.”

He was quick to add: “I mean, you’ve gotta be kidding me. Why would I buy a gaming system without a hard drive in it? How does this thing scale?”

Tretton didn’t stop there, and fired some remarks about Microsoft’s Kinect:

“Motion gaming is cute, but if I can only wave my arms six inches, how does this really feel like I’m doing true accurate motion gaming?”

Tretton didn’t seem to be done yet, and he had things to say about the Nintento Wii aswell:

“Our view of the ‘Game Boy experience’ is that it’s a great babysitting tool, something young kids do on airplanes, but no self-respecting twenty-something is going to be sitting on an airplane with one of those. He’s too old for that.”

I fail to see the need for the CEO to pass such comments about either systems and it remains to be seen if Microsoft or Nintendo would like to respond to these.

The PS3’s gaining momentum but still rests at third spot, in terms of lifetime sales, behind the Nintendo Wii and Xbox 360.