Hi,
Based on my experience, there's no built-in feature to integrate Outlook with SharePoint that can sync calendars events to sharepoint calendars list.
But one approach I can think out is to create the calendar file(ics file) programmatically that contains the personal events. And then import it to sharepoint calenddars and add this item to sharepoint calendars by using SharePoint Object Model via C#.
For how to create and add ics file to sharepoint you can check these links:
asp.net method:
http://webdevel.blogspot.com/2006/02/how-to-generate-icalendar-file-aspnetc.html
3rd party dll, DDay.iCal:
http://www.codeproject.com/KB/macros/iCalendar1.aspx
Also you can have a look at this similar thread:
http://social.technet.microsoft.com/Forums/en-US/sharepoint2010programming/thread/ee1345d8-c2c8-49e6-82de-5634f51d5b44
Hope this can help.