If you want to take a risk, there will be these: http://moon-audio.com/JustAskDrew/2013/01/ces-2012-final-impressions-by-drew-baird-of-moon-audio-lookout-for-king-sound-electrostatic-headphones-and-amps-here-soon/
$1k SS $2k Tube
It's funny that you should mention it, because I stopped by my local Audeze dealer today after work to pick up my new LCD3, yay, and I happened to mention that I was looking into some electrostatic headphone rigs. He asked me if I could hold off a little longer because kingAudio, of which he is an authorized dealer, will be releasing an electrostatic headphone and amp combo very soon to compete with Stax. He mentioned that it would be ~$1000 for the combo, which I assume is the SS version from that link you posted. He didn't mention a tubed version at all.
I have to admit, I'm kind of curious about this new contender. Plus, he should be getting a demo unit that I can actually take a look at. And, as luck would have it, there is also a Stax dealer in my city. My plan is to take my time and demo as many units as possible before making a decision. Now I just have to figure out how to get my hands on the Koss ESP-950 for a demo.
Sitting here listening to my new LCD3 as I type this and WOW, so much smoother and more refined than the LCD2.2 that I just returned. Much more detail as well.