It's been a couple of years since I have visited the JEDEC (JEDEC Solid State Technology Association, formerly known as the Joint Electron Devices Engineering Council) website. The last time I looked, they said they weren't going to do a 1066 standard. Should have went back sooner.
a recently published JEDEC standard for DDR2-1066 specialty (their words) RAM. After wading through nearly 100 pages of a pretty technical document, I believe that the simplest way to tell if a particular RAM is JEDEC compliant is to check the vcc. If the vcc is 1.8 volts +/- 0.1 volts at 1066 frequencies, it may
be real 1066 RAM.
I checked the specs on the MT47H128M8CF-187E RAM. It runs at CL7 latency. Considering that CL4 DDR2-800 RAM is commonly available, and most of it will run at CL5 at 1066 speeds, I am not sure that the CL7 latency is really worth it.
But you are right. True DDR2-1066 RAM does exist.