Quote from: kjj on June 22, 2011, 03:00:07 AM

From day one it has been understood that coins could be and would be lost.

Absolutely so. Coin loss, even delibrate coin loss, has always been part of Bitcoin.

Several times, Satoshi proposed deliberate coin burning as a way to use Bitcoin for escrow ("deliver the goods, or else I burn the coins that would otherwise be your payment") or document timestamping ("burn some coin to record a document's hash in the block chain").

Here are some references:
http://forum.bitcoin.org/index.php?topic=750.0
http://forum.bitcoin.org/index.php?topic=645.msg7712#msg7712
http://forum.bitcoin.org/?topic=2162.msg28533#msg28533

The number of coins is totally arbitrary, as they can just be subdivided to the necessary level of precision. Bitcoin could function with any number of coins (even less than one, if the number of decimal places is increased).

Coin loss is nothing to worry about (provided that it's not your own coins being involuntarily lost, of course).