30% gain clock for clock would likely be Intel's target.....16ops per clock vs. 12 with C2D/Q. Not the revolution from P4 to Core gave us with a 100% gain, but still quite an achievment. Not only are we seeing an increase in ops/clock with Nehalem, we're also going to see an evolution in memory bandwidth available. So far all the benchies are in DUAL CHANNEL DDR3, Nehalem is going to support TRI CHANNEL.
Lest we forget our lessons with Penryn and Wolfdale- the 45nm process has shown to OC very well with low TDP, although they are somewhat voltage sensitive. The "Tick" of Nehalem will be interesting indeed....Hopefully "Tock" die-shrink to 32nm fares as well as the 90nm--->65nm shrink did.