Would be awesome indeed! Just to list what's being done right now to reach this goal (feel free to add to this!):

Heavy experimenting to connect HIDs (keyboard + mouse) to the N900:
- Through bluetooth, or
- Through USB host mode. This would pose a problem for power input though, since the N900 can only be charged through its USB port.

Efforts are also being made to be able to print directly from the N900.

Together with more software becoming available that supports office working (FreOffice and ofcourse the full OpenOffice package through easyDebian) the N900 is well on its way to replace the desktop PC... AWESOME!!