Scoble mentions the Windows Smart Client version of Outlook in this post. This will be a very cool demo of the power of downloadable clients as long as it runs as a pure smart client, i.e. only running code from the download cache and only using isolated storage (and any other features of smart clients I can't think of this early in the morning).
Robert's post ends with a cryptic comment:
So, take that further. In 2005, what will Mozilla look like? And what will Outlook look like? What will your apps look like? That's why you'll want to be at the PDC this year.
Why Mozilla, are Microsoft doing something with Mozilla? A plug-in for WinForms smart clients, or more?