I dont see it anywhere. What's the story?

Matt Cutts :
"I think the Gmail integration will make it to everyone who signs up for Calendar. My guess is that some people are on servers that got upgraded first, but it should make it out to everyone over the next few days.

(I'm just guessing though.)"

Also, make sure your language is US English.

And have signed up for calendar! (http://calendar.google.com)

it is US English! And I have a Calendar that has a lot of stuff on it--it doesn't show up in GMail nor do I get the pop-up notifications. I get them thru email tho.