Would just like to point out that amending existing events to 're-use' them is considered bad form around here, as it messes with people event lists and makes the Flickr tags confusing.
This is really an issue with upcoming. If you have a regular event, it makes perfect sense from a user's point of view to be able to clone a previous one.
BREAKING NEWS:
This month we'll change venue to fit more people in, but still get access to free Wi-Fi and coffee. Plus I'm delighted to announce that TrustedPlaces.com will be sponsoring the coffee.