Not posting to quibble Lopri, but I am curious whether you are more specifically interested in determining if 1.8V DDR2-1066 sticks exist or are you more specifically interested in whether DDR2-1066 sticks are available which are JEDEC spec certified?
Both are good questions, but you seem only interested in whether something is JEDEC approved insofar as whether it is certified to operate at rated speeds at 1.8V. (a worthy question, but nonetheless not at all what I thought the thread was about)
For what its worth the "built to JEDEC spec" notion applies to the extent that the spec requires memory hiearchy to be obeyed (rows, columns, layout, etc) but no one in the fab actually makes a product to a JEDEC spec in the sense of what you are probably thinking. They start a bunch of wafers, do their best to process every chip the same on each wafer, and the speedbin out the parts at the end of the line.
Whether a DDR2-1066 chip came from a wafer that also contained DDR2-800 and DDR2-667 chips is irrelevant insofar as labeling that DDR-1066 chip as being "JEDEC spec". The specific thermal/voltage/timing profile of the chip merely needs to meet the specs requirements and it can be said to be "built to spec".
Meh, I'm probably still not shedding any light on the topic but I'll leave my post perchance someone finds value in reading this perspective. (Texas Instruments used to make RAM until they sold the business division to Micron in 98-99).