I have seen several posts saying it cannot be done, but I just did it, kind of... 🙂 . Here is what I did. This doesn't officially make the default contacts folder be iCloud but in the end, I simply want my contacts to pull up easier from my icloud contacts when I create a new email and this does the trick. Note If you create a new contact inside of outlook, it will default to your other folder (not iCloud) but simply click the iCloud folder on the left and start creating all of your contacts you need, they will be placed in the iCloud folder at that point. If you create them on your iphone they will be synced and updated to the iCloud contact list provided you have your phone settings to allow you to sync contacts with icloud.
1. From the top menu on the Home tab, select address book. You can also get to this by creating a new email message and clicking the to tab, this will open the address book.
2. Once the address book is open, select tools and then options from the address book menu.
3. from the drop down, choose the custome option and then select iCloud. This will select the iCloud contacts folder first when opening a new message.
4. Choose the iCloud option in the drop down for when opening the address book, show this address list first.
these settings will default iCloud as the default contact list from a user perspective when you open the address book and when you create a new email.
I dont know if this works for 2010 but you can try to see if there options are here.
It appears there are still issues saving incoming invites to the default calendar....ugh!!