Forgive me if this has been posted before, but I could not find it anywhere. I might have figured out a temporary solution to syncing your iCal to do list to your iPhone if you have IMAP capability.
If you have your iCal To Do Items synced with your Mail (I have them synced, but cannot find where to choose this option in preferences) select all your To Dos in Mail from "On My Mac" to the To Do list in your IMAP account.
All the To Dos should be send to your server and synced with your iPhone. It's not pretty, but it works...
Then again, if you're like me and you can't receive email on your iPhone because of the software bugs with the new update it doesn't really matter:( I have to reset my network about every 30 minutes for my Mail to work. Being a new iPhone user this is extremely upsetting