Quote from: cloud9 on June 29, 2011, 09:28:08 AM

btc transfer fees are not a requirement to be included in the blockchain at this stage.

Maybe you should read through this thread to see what happens when someone tries to make a 'no transaction fee' client
http://forum.bitcoin.org/index.php?topic=22434.0

If a lot of transfers are going through, and or the amounts are small, they will be paying a lot more than they are now unless they wish to hold the payment in BTC for hours/days before cashing out. This basically rules out micropayment bitcoins, as well as instant cashing out, forcing an extra fee (passed onto thte customer) to insure against exchange movement, unless the exchange rate really anchors down (which I hope)