A few thoughts on this,
1) If it’s someplace like CV (close to where they need to be) I would think people will be less inclined to walk because they need to live somewhere anyway and if they can afford it why move ? (unless forced of course or they just want to buy an even better place, I have heard of it happening, its not that rare for a short sale after the owner buys another even more upscale home).
2) I think Banks are more willing to talk to you if you owe 1 Million or more. (I heard a Joke once, When I owed 100K no one would talk to me, but now that I owe 5 million they call me !!).
3) There are fewer people who can afford the high end even after the decline, so yea there may be some deals out there.

One more
4) Even though the percentage has gone up, the absolute number is still probably fairly small.