albo - 12:10 am on Oct 13, 2011 (gmt 0)
It's a lo-o-ng download. Then, if you want photo streaming on the iCloud, there's a new release of iPhoto to buy ($15) and another somewhat long download (782M).
Warning, if it matters: if you want to use iCloud, and if you use Gmail, you can't sync Contacts with both iCloud (i.e. local address book) and Gmail. Pick.