Of course this may seem simple to a lot of you but I keep seeing this question so I thought I'd post it for the Google monster to help others. When you open the Bulk Insert Task for example, the DestinationTable is a drop-down box. This is fine except in the scenario where you must point to a table that was created in an earlier step of the control flow. To do this, just leave the DestinationTable property blank after configuring the rest of the task. Click OK and you'll notice a red icon on the task where it looks like it has an error due to lack of configuration. Select the task and go to the Properties pane. Now, you can set the DestinationTable property through the pane by typing in the table that will be created in the future. After you set that property in the pane, the red icon disappears and you're ready to roll.
This works for almost any property with almost any task or connection.
-- Brian Knight