I'll just observe that what matters to most of us is what's on the market now (or coming very soon), not what might be achieved if a third party software company had access to an NEC developers' kit.
I've been using the NEC 2690 for two months now. I purchased it bare at first, with no calibration software, and started using it with my Spyder2Pro setup. I was very pleased with the results compared to my two year old Apple 23" display. Colors were more even in their saturation and lulminance, corner to corner. I was pretty pleased.
After reading threads like these for a while, however, I couldn't leave well enough alone, so I bought the Spectraview software and colorimeter (which at the time was on sale).
The difference is just startling. It's as if I clicked on a neutral gray card and a color cast came off the screen. The colors all just popped where they should pop and receded to neutral where they should be neutral. I've been calibrating digital displays for at least six or seven years now and haven't seen an improvement like this - it's a real breakthrough.
Most important, when I use the display in a color managed workflow that includes soft proofing, I am thrilled with the match between screen and paper. It can't be 100% of course, as transmitted light and reflected light are inherently different. But this is a leap ahead of the Apple/Spyder technology many of us have been using for a long time.
One feature I quite like is the ease of shifting among personally created calibration levels: I like to use a reduced brightness level for "general" computing - internet browsing, wordprocessing, etc. For Photoshop and related work, I shift up to a brighter level that I find a little more accurate for critical work at the extremems. Very nice.
Is the Eizo better? I don't know; it's probably as good from what I hear, but their products are much more expensive. On the other hand, if Andrew says the NEC is close enough, I'll take his word for it. I attended one of his "advanced" color management lectures back in the days of Photoshop 5 or 6 (can't remember which) and I know he's got no axe to grind. He's universally recognized as a neutral expert in color management, and he's recommending the less expensive device!
So if you get the NEC, buy the whole package (software and hardware) and relax for the next number of years, till the next breakthrough.
My two cents, as they say.