Well, someone on the Google forums has figured out a work-around for this widespread problem. Thanks to Level 1 and Jennska for posting this! BTW, it DOES work if you do it right. All my Google calendars are back up on iCal and working flawlessly!
Login to Google Calendar via a web browser (Safari, Chrome, Firefox)
On the left side, locate Other Calendars click on the triangle to the right of it
Select Settings from the menu
Scroll until you find the calendar you want to add to iCal
Click the calendar name once
On the Calendar Details page, look towards the bottom for Calendar Address
On that line, go to the right until you find (Calendar ID: ThisWillLookLikeEmail@GoogleOrSomeOtherDomain.com)
Copy just the part after the colon and before the ending parentheses
Paste it into something (Textedit doc, Word, Stickies, whatever)
Copy/paste the following bolded text before the Calendar ID: https://www.google.com/calendar/dav/
Copy/paste or type the following bolded text after the Calendar ID: /user
You will end up with something that looks like:
https://www.google.com/calendar/dav/thiswilllooklikeemail@googleorsomeotherdomai n.com/user
In iCal, select Preferences from the iCal menu
Click on Accounts
Click the + button below the list of Accounts
Give it a description, can be anything you like.
Enter your user name. Note that if it is not a Gmail username, you need to enter the @domain.com part also, critical for Apps for Education or Apps for Business that use their own domain
Enter the password for that account.
Click the triangle to the left of Server Options
Copy/Paste the address you created in the above steps into the Account URL: box
Do not check the Use Kerberos v5 for authentication
Click Add
The Account Description name will list on the left side of iCal, with a flip down triangle to see the calendar associated with the url entered.
