Outside of Los Angeles, they have returned. Here is a BBC report where they interview people who have lost their homes due to foreclosure, and who now live in a tent city:
http://www.youtube.com/watch?v...
It is unclear how many live in this tent city - the report doesn't say. From the video, I would guess that around a hundred tents are visible, but there could be many more.
There is already a diary at dKos about this:
http://www.dailykos.com/story/...
Someone suggested that these tent cities be called Shruburbs.