You'll be able to watch the whole retreat on video! If you don't want to be on the computer, you will also be able to listen by phone or online, as far as the meditation and sharing sessions are concerned, and possibly for some of the conversations with the speakers.
As far as your own participation and contributions go:
During the meditation and sharing sessions, you'll probably be able to ask questions and share your experience through Google hangouts if you're familiar with that platform. If you're a low tech person, you will be able to listen and call in by phone, or online. During the sessions, you can use the comment section of the YouTube channel on which the sessions will be broadcast.
As all these aspects are coming together, the retreat is starting to be more and more real. I so look forward to sharing it with all of you!