While I dont completely agree with esmith there is alot of truth in what he says. Prior to the funny money credit era, a move-up was typically no more than $150,000 and usually closer to $100,000. The Int only, NINJA loans allowed people to take a couple steps up and we are seeing that unwind nowadays.
Moving up $100,000 generally represents an increase in your monthly housing costs of about $1,000. That in turn requires another $30,000 to $40,000 in annual income to be an easy move. The monster jumps in homes by the majority of move-up buyers are a thing of the past IMO.
I expect this to lead to more of the moving around in a community and less Oceanside/Vista to Encinitas/Carmel Valley jumps. Most people who need a little more room will have to be content finding it around the corner. If they desire to move to a more desireable area they will have to be happy with much less house in most cases.