Let's return to our familiar format of Q&A.
Q: Can I move calendars from Google to iCloud?
A: Yes! Yes you can!
Q: Is it easy?
A: Yes! Yes it is! In fact, it's a million times easier than I expected. It's actually way easier than syncing contacts and revising all of them, and definitely easier and faster than the actual iOS 5 update process!
Q: Okay, what do I need to know?
A: There're a couple things. Here we go, numbered points style. Hopefully the pics will help you out.
 Export all your calendars from Google calendar. Open your Google calendars in your nearest web browser. On the top right corner, click on the Gear symbol. Select Calendar Settings. Click on the Calendars tab.
You will see the following screen. At the bottom of the page, click on Export calendars. What this does is it will make a .zip file containing all of the calendars.
 Open iCal. Go to File > New Calendar > iCloud. Give it the name of your choice.
The calendar will now appear in your Calendars list.
 Open your Finder window. Double click on the .zip file. Doing so will put an uncompressed copy of the folder in the same location. Open this uncompressed folder, and double click on the calendar file (ends with .ics) of your choosing. Even though the name will be long, the calendar name should be there at the beginning of the file name.
 You will receive a 'warning' which you can ignore. Click Open.
 You will be redirected to iCal, where you will be asked to select which calendar to place this file. Select the iCloud calendar you recently made. Click on OK.
 That's it! Now you're done. The Google calendar has been successfully imported into the iCloud. These events will appear on any iOS 5 device that is syncing calendars using iCloud. If you want to check that everything is in order, visit www.icloud.com. Only calendars that were successfully uploaded to iCloud will appear in the browser.
Of note, to make life easier, you will probably want to the iCloud calendars your default. To do this, go to iCal > Preferences. Change the Default Calendar as desired.
To read Google's original directions for the procedure, click here.