The 1% controls 42% numbers were made for 2004 though. It may had made mathematical sense back then. Plus after 2008, there are more people in debt or bankrupt, with a negative net worth fueled by the economy. The not-so-rich people with home forclosures, I'm guessing many of them are in negative net worth, and we don't know where to get these numbers.
I'm sure a lot of the population today hasn't done calculations to the point as we did to figure out where it really stands.
I kinda liked my own definition of "what it takes to be in the 1%" a little better because I had an idea of what I was talking about. These days having 500,000 - 999,999 might not make you a millionaire, but at the same time we have to consider the "new cool kids group" should be 5million, 10million like Daredevel7 said.
In that definition, since we know that billionaires and millionaires are 3 or 4-5%, it would knock down the percentage even lower on top of the negative worth people.