A new option has been added to User Preferences for determining what happens when a patient chart is opened from the Schedule or Chart Find. "Open Primary Note for Recent Encounter" will launch the patient's chart and automatically open the primary note for an encounter within the last three days.

Go to User Preferences > Home/SysWide > Schedule - Double Click on Appt Action: 

Or go to User Preferences > Chart > Open from Patient Find - Also Open:

Please note, Primary notes are set on the note template in Admin > Note Templates.