When you go to your schedule and see the "Leave" box, that means you are in that class. If you don't want to be in the class, then click the "Leave" button and it removes it from your schedule. It saves your selections as you make them, so if you log out and back in, they should still show up. You can export the iCal schedule to Outlook, if you want to open it there. I think this is just to give us a visual idea of the classes that we want to attend. I imagine that we will still have to register for the learning classes, when we check-in.
Dang too slow. What Arnold said 😄 I think the online thing is nice - to a point. It's missing a chart view of the schedule that shows me where the sessions overlap. The current layout makes it very hard to flesh out my schedule without conflicts since not all the sessions are the same length. Didn't we get a packet last year prior to the conference that had a nice chart showing the sessions in a time grid? I miss that. BTW - Anyone else feel like there isn't as much actual Pro|E choices as last year? Seems to be lots of CoCreate and Windchill stuff, but I was a little disappointed in the Pro|E specific offerings. Some time slots have only one Pro|E offering. I clicked on several promising looking topics only to see that they were for CoCreate, not Pro|E.
To answer your first comment; clicking on LEAVE removes it from your schedule, that's why it un-checks it in the schedule. To answer your last comment; no, adding it to your schedule does not mean you are enrolled... you need to do that at the conference itself (at least that's how I understand it... I'm a first time attendee).