Hello, guys! I answered this question on Quora and I thought you could be interested in that, too.
I found an interview with the guy who traded these pizzas for bitcoin. This is an excerpt from the interview:
Q. What do you primarily use bitcoins for? Do you still control millions of dollars worth?
A. Bitcoin as a currency is meant to be spent. Those 10,000 BTC made it back into the economy fairly quickly, around the time they were worth some $400
