That was the message I received just as many others may have received something similar. However, when I clicked the link "Upgrade to Outlook" (and I clicked this on two different occasions today), I received this page.
So it looks like I'll just have to wait for Microsoft to force me into the update. One of my other accounts was updated and this is how it looks.
It's a big jump in change, but nothing really fancy. I really don't like other UI as the other one just looked ugly and this one reminds me of that Metro design that I absolutely hate.
Has anyone been able to update? Do you like the change, don't care, or hate it?