Transistors may be shrinking but atoms are not. Transistors are now just a handful of atoms so it matters even more when a couple of those atoms are out of place. Process variations, whether they are statistical, proximity, or otherwise, have got to be thoughtfully accounted for if we are to achieve the low-power, high-performance, and high yield design goals at 28nm.
Catalog of SIP Cores
System on Chip design resources
System on Chip design resources