At this time (July 22nd, 2007), Barca can only import emails and contacts from Outlook, not tasks nor calendar items.
Just to "test things", I have created a simple application (small by code, but unavoidably large by download size due to the programming environment used), that can import tasks from Outlook.
Functionality is not guaranteed, it doesn't import all the details yet (only start date, due date, subject, notes(body) and date of completion are imported).
Tested shortly with Microsoft Outlook 2002 on Windows XP.
Future plans:
I might add support for more task properties through time, but I don't guarantee any further development. It's only made available thinking that someone might find it useful ("better import something than nothing"). I might even consider adding calendar import functionality, again that depends on time available and my learning desire (this program is just a by-product of my efforts to learn programming).