Intel's upcoming Pine Trail-M platform is the new codename for the all integrated Atom and you'll see some significant savings in space.
Netbook 2008, the platform made from Diammondville 45nm Atom, 945GSE + ICH7 was measuring 22x22nm for the Atom, 27x27mm for i945GSE chipset and additional 31x31mm for the ICH7M.
The new Pine trail-M (M stands for mobile as D stands for Desktop ed.) has only two chips and even these two got slimmer. Atom now measures 22x22nm but it has also swallowed the IGP, while the only other chip, now called NM10 express chipset, what is left of Southbridge measures just 17x17mm.
This saves a lot of space and makes the passively cooled netbook a reality.