In future there may be additional reasons to have conduit running all
the time, such as 'always up to date' sync (only our gconf sync uses
this ATM, IIRC).
The Tomboy and Folder plugins support Always Up To Date, and in a couple of days the windows mobile stuff will too. Evolution could, but the bindings need more love, IIRC. F-spot may. We implemented the dbus support in F-spot, so i suspect its possible.
(For non conduit people, Always Up To Date is when an application tells conduit to sync because a change occurred. These are always in direct response to a change and never done on a timer. Polling for the fail).