A dual core is not really preferable on netbooks, because they will suffer battery loss.
Unless Intel integrated a technology that successfully disables the second core when not in use (or not needed), a second core in a small netbook only adds up to heat, and loss of batterylife.
It's performance will still be below notebooks, and it's battery just above.
I'd rather have them push the Atom processor to a die shrink, and give it under/overclock options to run at 600/1000/1600/2000Mhz.