The report was published over 5 days, each focusing on a different perspective of the data. The link above takes you to the main page, you'll see day1 thru day5 navigation in the middle of the page.

Another way to look at the active versus inactive blogs:

According to a 2008 survey by Technorati, which runs a search engine for blogs, only 7.4 million out of the 133 million blogs the company tracks had been updated in the past 120 days. That translates to 95 percent of blogs being essentially abandoned, left to lie fallow on the Web, where they become public remnants of a dream — or at least an ambition — unfulfilled.

I like the way you put this into perspective. That is an impressive figure!

With such low barriers to entry, I'm thinking that 2% is actually a stunningly high success rate. I would have guessed it was more than one order of magnitude lower. In the terms you expressed it in, I'd have guessed it was less than 10,000 people.

So, Internet, if you're enabling 400,000 people to make a living in just the blogospere, bully on you, you rock!