I don't see any real reason why that trend wouldn't continue for the foreseeable future.

While I hate Zestimates and really any online estimates for a single property they do have those zip code trend lines for average listing price, etc.  

Few are listed below:      1.Art glass awards      2.Crystal awards      3.Engraved awards     Which do you think would be trending now?     

To grasp why a home would go into default then foreclosure, that eventually leads to the property being an REO, you have to wrap your mind around the dynamics of economic trends in this country.

Has anyone else noticed this trend on Hubzu.com in their market as well?

The result of this trend is prices rising faster than incomes, homes staying on the market for fewer days and a limit on just how much home sales can grow.for more details see NYT

I would think having a feed from the MLS which is the most accurate would be good to see what comes available and also to watch Market trends.

Is there any source of information or data where i can get a better understanding of the drivers of this price appreciation - is it a longterm trend or a bubble? 

I definitely see a trend of a lot of Angelinos looking out of state.

There is a slight trend of millennials being more interested in renting vs. owning homes.