Updates are released by your carrier and not by Samsung. Samsung sends them to the carrier, the carrier tweaks it, adds some, deletes some, personalizes it, then sends it out in waves to prevent crashing their server's trying to send a 2gb file to several million customers at once.
I'm on AT&T and I just got mine 2 days ago. So the first question we ask when someone wants to know where is the update, we ask what carrier are you using?
Some carriers have released the update. Some are still tweaking it. Give it time. It's on its way.
If you go to Settings > Check for Updates and click that, it only actually scans one time a day. You have to wait 24 hours before it will actually do a scan. At least, thats how it works on AT&T. You have to remember that these carriers have MILLIONS of subscribers, so the updates are distributed in waves. Otherwise their servers would go into meltdown. When you get it depends on where you stand in line. Some of my updates came on the first day... others came a week or so later. Luck of the draw.