I was at CVS in the Mt. Kisco Square shopping center today and noticed that there is a new Thai restaurant where Myong used to be. The name is Mana Thai. They do not seem to have a website but do have a Facebook page (without menu). I picked up a menu, prices seem reasonable. They only have 4 or 5 tables so I'm guessing most of their business will be take-out. They claim to offer delivery. If I get a chance to scan the menu I will post it here.
BTW, Myong is apparently re-opening down near TJ Maxx according to their website. I guess they figure that being closer to Chappaqua they will have more people who will pay their high prices.