Depending on how old you are, even money that it'll happen within your lifetime. Heck, I just passed 50 and I'm pretty sure it will happen within mine.
Not to you, though. Gene alteration happens to embryos, not grown adults. And even if it happened to grown adults, it'd be a very select few for a couple of hundred years at least. I'm afraid you'll die of old age at the usual time. Don't get your hopes up!
You're mainly right, though. Kids being born right now can expect to live past 100 (not through this process though). I expect it's the next couple of generations who will start to see the benefits of this.
We're the unluckiest generation ever. We'll be one of the last to have to die of old age. In a thousand years people will look back and think how much it sucked to be us, just a short distance form immortality but we had to die before we got to it.
Kid to mother: "What they all had to die?"
Mother: "Yes, everyone. They got about 70 years, then they had to die."
Kid: "What? ALL of them? They HAD to die? No choice?"
Mother: "Yep. Life was a death sentence. It was a truly dark age. A day when DEATH was the fate of everyone."
Kid: "Man, if I thought I had to die, no choice, I'd go insane."
Mother: "They pretty much all did. When you're older you can watch some vintage news footage. But it's all rated R for Ridiculous, so you'll have to be 18."