Here's an interesting chart of how distributed the wealth is in Bitcoin

The richest 1% of United States families controlled a record-high 38.6% of the country's wealth - CNN news.

How's that for Bitcoin?

The top 100 addresses control 20% of the wealth.

What's interesting is that the slope is declining. This could indicate that wealth gets more distributed over time.

When Bitcoin started in 2008 by Satoshi Nakamoto, all of the wealth belonged to a few individuals. Bitcoin was only a couple cents at the time anyway.

Then in 2009 many Bitcoins were distributed among the young crowd interested in this technology. This was the most equal situation we've had!

In 2010 a centralisation took place. Now we're quite steady, and bitcoins are getting spread out among more addresses again.

More people are holding bitcoin, and perhaps whales and exchanges (the largest holders) are holding their bitcoin in multiple addresses now.