By switching to the top 500 address list there are a number of wallets with no activity since 2010 and 2011. The probability that these are LOST addresses is high as is the value.
Anyone want to work out the % of coins involved?

This is very interesting on a theoretical point of view. What would you need to get the bitcoins in those wallets? Each address has a public and private key. Where is the public key published? Also, couldn't you just brute-force the discovery of the private key?