no background processes?
First of all, let me clarify my statement about a duel core running 2 programs simultaneously. I don't mean you can only have 2 programs open at once.
Each core can do 1 operation at a time. If 50 programs are open the computer will do a little bit of program 1, stop do a little of program 2 stop, move on to program 3 and so on.
It only appears as if your computer is doing things simultaneously because it is operating at such blinding speed.
For example, if you are running 3 programs at once on a home computer that operates at over 2 Ghz you can't tell that its not running all 3 programs simultaneously.
BUT try opening 50 programs and you will see a signifigant slow down because the computer must divide its time amoungst so many programs.
Multi core means that you can run true parellel operations. So, a quad core can run 4 programs simultaneously, without being slowed down by need to keep switching amoung programs. Could you run 50 programs? Sure, and it would be 4 times faster than on a single core computer that was also running 50 programs.
Of course with all those cores you need a lot of RAM, but lucky for us, memory of all kind keeps getting cheaper and more plentiful.
As for Apple never allowing background apps.
Rumors abound on this website that background processes could be part of OS 3.0.
http://www.iphonealley.com/news/background-processes-coming-in-30-iphone-software
http://digg.com/d1hZ7q
Here's a link to an article about a quad core Iphone.
As for the CPU speeding up, the 620 MHz chip now in use was also there for gen 1. At some point they will upgrade it to a faster chip.
As for multi-core useing more energy, I don't know about that. ARM has the Cortex A-9 specifically designed for smart phones. If a quad core CPU destroyed battery life then would anyone be useing it?
Even if multi core did suck more juice, lets not forget that better electronics in accordance with OLED screen will double or even triple battery life on the same battery.
Through in a Silver Zinc battery that extends battery life 40% over current Lithium Ion and you have 4 times the battery life of today's Iphone.
This kind of energy storage+ efficiency opens up a lot of options for apple.
They could offer an Iphone with 28 hours of Video, but it wouldn't be any better than today's model and it would allow people to own their Iphone for a decade without replacing it due to a dying battery.
They could go Duel core for at least twice the battery life, mixing 14 hours video with parellel application ability.
Or stick with 7 hours of video with a quad core and all the abilities that go with that.
Of course that is assuming that multiple cores multiply the power drain which I am not sure about.
One thing I do know is that Apple has said that the Iphone will be turned into a world class gaming platform.
Already game designers are beginning to develop games around multi-core platforms such as the PS3, (octacore) and the X-box 360, (tri core).
Half Life 2, for example, will be specfically designed for Octacore operation.
If apple is serious about making the Iphone/Touch a gameing platform they will need to go Multi-core, (a quadcore Iphone would be able to provide better gaming than a PSP)
And if that means ever better batteries are needed, well so be it.
Researchers at Stanford have discovered that by useing nano-silicon wires in the cathode of lithium ion batteries they can store 10X as much energy as before. The techniques to make these nano-silicon wires can quickly be adapted by the existing silicon electronics industry, so we will be seeing these super batteries soon.
Thus by 2015 it should be possible to combine more efficient electronics with OLED and these Super Lithium batteries from Stanford to allow for a 30X fold increase in battery life.
Since the utility of 210 hours of video is limited, the extra battery life can be rerouted to running faster chips on multicore CPUs.