There are three extra details to fill in:

- Start Date

- Event Location/Venue

- Venue phone/email

Only Start Date and Event Location are mandatory fields.  When you save an event topic, there will be a "Join Event" button at the top of the topic page.  You can simply click this button and your username will be included in the event.  The details of the event display at the top of every page in the topic.  Gone are the days of just adding your name via a post.  Event topics display in the topic lists with a calendar icon to the right, so you can easily see that it's an event.  I've used one of the upcoming rides to show how this works, example below:

Link to this event topic: