It’s growing, for sure. Pew’s analysis of Census data found shows that 21.6% of Americans ages 25 to 34 living in multi-generational households in 2010 vs 15.8% in 2000 and 11% in 1980.
The percentage has doubled since 1980. I graduated from college at the end of the nasty stagflation recession in the early 1980s and had to spend nearly a year with my parents before finding my first "real" job. Moving back in had everything to do with not being able to find a self supporting job. This is another data point that flies in the face of the return of the boom times.
I see a lot of anecdotal evidence all around me. Young adults, sometimes with their own spouses and/or kids, have moved back in with their parents in two of the houses on my block. This to the chagrin of their parents. One of my wife's friends, in their late 30s, have moved in with their parents twice in the last four years due to job losses. I hear similar stories from colleagues at work.
Moving back in with parents is not cooler than you think, as the OC Register suggests. It is simply a matter of necessity for the less fortunate proles.