Canon has announced the availability of a locking mode upgrade for the Canon 5D Mark II and 7D, which will prevent the settings from accidentally being changed. For now, the service upgrade has only been announced for Japan and will cost 10,500 yen (roughly $125 USD).
No word yet on the availability of this service upgrade in the US or other markets.
Is this a feature that you would want? Will you pay for the upgrade if/when it becomes available in your market?