That 40% sounds like typical marketing talk.
Unless they're talking specifically about IPC, I'd take that with a bucket full of salt.
Well no - its what happens when you fit 4 cores in instead of 2. Actually its not that impressive when you think about it. But it is likely to be the biggest single year jump for some time. They are not going to increase cores again in next few years - they will simply optimise the quad-core's and hexcores for few years to come and we will be back to 10%-12% annual improvements (if that).