Elusion11: Do you know what you're talking about? Core1+2 were based off the Pentium III. Core i7s first iterations were that same Core2 base, a small number of new SSE instructions, plus stealing their un-core from AMD. Sandy Bridge re-introduced some Pentium IV-isms, which did next to nothing for IPC, but did allow slightly higher clocks. Albeit, the stock clocks aren't any higher, because they won't last at those frequencies, but it does boost their image.
Then of course, they continually bloat the x86 standard by adding new instructions, which they may or may not let AMD and VIA use. Many apps still choose to be compiled for i386, i686, or basic x86_64, except for the benchmarks you see on sites like Tom's which are almost all compiled with ICC, with optimizations for Intel's latest(but not AMD's).