"SSE4, also known as Nehalem New Instructions (NNI), is a new instruction set for the Intel Nehalem microarchitecture, which is slated to be released in 2008"
"What is now known as Supplemental Streaming SIMD Extension 3 (SSSE3) was also referred to as SSE4 by fans during development of the Intel Core microarchitecture. This has caused a bit of confusion in the community. Vendors such as NewEgg have mistakenly marked some of the Core 2 processors as having SSE4, when they actually have SSSE3."