I'm pretty fortunate. In fact, I'm doubly fortunate.
Not only was I invited to Google+ when the only way to get in was to have a Googler personally recommend you, I was invited twice. How's that for bragging rights? When everyone was begging for these invites, I had two.
But enough of me bragging about my random luck that has absolutely nothing to do with my own skill or worthiness. I've seen a lot of people comparing Buzz and Google+. Or comparing Facebook and Google+. The general consensus seems to be "I've seen this before."
Well no shit.
Google+ isn't radically new like Wave was... which is probably for the best. Instead, it takes a bunch of things we're already used to (photo sharing, update streams, tagging friends) and puts a Google spin on them (I, personally, love Sparks—Google's way of making it convenient to introduce new content into your stream).
What I find interesting (and mildly amusing) is the comparisons that people are making. I've said that Buzz is to Twitter as Google+ is to Facebook. But that is really missing the point. There are two names missing from that analogy that should be there: Jaiku and Orkut. Jaiku was Google's first attempt at a Twitter clone—to be perfectly accurate, it wasn't Google's; they bought it. Orkut was Google's first stab at a Facebook clone. As Jason points out below, I was mistaken. Orkut was Google's first stab at a Friendster clone after Friendster refused to sell to them. Facebook, as it turns out, was an iteration on Friendster (see The Facebook Effect, page 86: "'We were really worried we would be another Friendster,' recalls Dustin Moskovitz"). Which, all-in-all, I think serves my point more than it hurts it, but in the spirit of absolute accuracy, I've amended the post. Good catch, Jason.
You've never heard of either of these, and if you have, you don't use them. And that's why they aren't being placed in the analogies. That's why they aren't being mentioned at all.
It's important to remember, though, that Google believes in iteration. I don't think that just means iteration on a single product; I think that means iteration on their entire approach to a market segment.
I don't know if Google+ is going to catch hold. I don't know if it will go the way of Buzz, or go the way of GMail. I hope it works. It's too early to tell, though, despite "insane demand". What I do know is that social is important to Google. And as a company with nearly bottomless pockets, Google has all the time and cash it needs to iterate through product after product, learning as they go. Is Google+ the end of their quest for social? Only time will tell. If it's not, are they going to give up? I doubt it.
So yes, you've seen this before. And rest assured, if it fails you'll see it again. But failing to see what Google has learned as it has iterated over social products is failing to see Google for what it is: constantly improving, slowly but surely.