Competition: As opposed to the PS2, the PS4 is launching with at least one [arguable lol!] competent competitor. The PS2 also had tremendous momentum from PS1's domination of the previous generation.

PS4, in all practical senses, does NOTHING DIFFERENT. This is critical: keep things essentially the same and the market won't expand. This means PS4 will have roughly the same sales.

If only the PS4 did something amazing such as highly reduced development costs, I would be willing to rethink this disruptive thing over with the PS4.

The PS3 had very strong competition. If PS4 only has one strong competitor, then it would blow past PS3 sales. Since the market should also expand, even getting 1/3 the sales should put it above 100 million.

Yes?

Completely agree. Whoever has the best ecosystem will have the disruptive console, and the best will probably be the one that covers the most devices.

Sony will have PS4 streaming to Vita and VitaTV, and Gaikai to all of them plus PS3. They had Remote Play on Vaios, so I can see them looking into that, and Gaikai covered Tvs and browsers and was adding iOS and Android before the buyout. They are in what looks like the strongest position so far.

MS however is a wild card. They haven't actually revealed any plans, but the leaked document showed they were aiming to have Xbox experiences "Any time, Any Where, Any Screen" by 2015. If they have a better broader ecosystem they will have the disruptive console. They have the advantage of Windows in this case, so may leverage that. But too much is unknown about that.

maybe or maybe not ?

PS4 games should be cheaper than PS3 games.

Really ? Some source would go nicely with your claim if it were true. Sure the PS4 is more easier and all but did it make things easier drastically.

It's because we are moving more things to real time calculations. This is mostly to do with PS4 having so much power.

Instead of re-texturing for every single unique situation a model is put in, devs can just have it calculated real time. Real-time lighting, real-time reflections, real-time shadows, etc. All of these save a ton of time and work.

Here's the Killzone guys talking about some of this.

Edit: I'm talking dev costs of course, not end user price.

I've being saying this for years... the only sony console which was disruptive was PS1. And that's from the company which created the walkman...