I disagree 100%. My phone fulfills the full duties of a phone and a computer. I very regularly have several apps running at the same time and sometimes the dual core can't keep up. My data usage is regularly in excess of 5gb/month and thats not counting the time i'm on wifi. If a quad core gets things running smoother, i'm all for it. As for battery life, it really should splitting the load across more cores should add a little to the battery life. Will it be enough to notice? Who knows....
The big thing samsung is talking about doing for battery life is lowering the screen res. The phone i'm typing this on is higher resolution than my 19" computer monitor. Is the picture quality amazing? Absofreakinglutely! Would i even notice it if they dropped it down a tad? Nope. Since the screen is what eats up the battery so fast it makes perfect sense.