Mike, I know that you're excited about the possibilities for better and cheaper headphones in the future, but as Jason has said, an HE-90 type of headphone (pure electrostat) is very unlikely to come from Grado Labs. It's just not in the picture. In fact, I remember talking with John about this myself when I was at one of the NY meets that he hosted. I specifically asked him about the possibility of building an HE-90 or Omega II type of electrostat, and mentioned that I thought the RS-1 came as close as any dynamic headphones at reaching that sort of treble excitement and clarity, and his response was basically "not our market." I was quite impressed by this and just let the moment pass. He's heard all of the "best" headphones and is happy with what his company is doing. All of the products in the current Grado lineup are well positioned and competitive at their price points.
To tell you the truth, I don't blame him one bit. Electrostats/planers/ribbons have never been an easy market to sell in the high end "speaker world" and it would be even harder to do much damage to Stax in the high end headphones market (Stax is VERY well reputed among audiophiles, and has decades of experience behind them). Many companies have tried, and most have failed, or at least have died out after a long struggle. Magenpan and Martin Logan seem to be surviving in the long run, but the likes of Sound Labs and Newform Research seem to be struggling (not to mention Quad). So if there is such little space for speaker manufacturers in this sub-segment of an already limited (high end) marketplace for speakers, then what kind of volume could you hope to achieve with headphones? The market research would likely begin and end by looking at how Stax has struggled (despite their excellent reputation, they've had a TON of product failures over the years).
To invest valuable time, energy and capital into an area with an extremely limited marketplace, just doesn't make sense if you are John Grado. This is a company that has been around for 50 years, but yet has no experience whatsoever in the murky waters of electrostats. Why start now when you're finally at a point where you can watch the company that you've invested your life's work in crank out the product with cash cows such as the SR-60 and RS-1, etc. John strikes me as a very practical businessman, and one who has no false aspirations of setting the world on fire at this point in his life.
I'm not saying it won't or can't be done (i.e., an HE-90 quality electrostat for $3,500 or less), but I don't think it's realistic to expect a company the size of Grado Labs to take on this challenge. Given the current success of Grado's product line, the history of the company as a makers dynamic headphones only, and John's stated objectives, I'd be shocked if (by reading this thread or otherwise), he decided to switch gears and go into electrostats. The ONLY way this might make sense is if he wanted to develop a product line that would compete with Stax from top to bottom.
The better company to ask this question of would be Stax, but I suspect that there answer would be that an Omega III would do nothing but destroy the market they already enjoy for Omega II (a very successful product by all accounts, especially in the last couple of years).