Boy, a lot of this is true. I'm a dad four-times-over now, and yeah, there are definitely changes. I've had entire conversations with people where I had no idea what we were talking about because I was simultaneously tracking three highly mobile little Tasmanian devils, while interpreting the nearby cries of #4. It is almost impossible to do anything else while the kids are present -- my mind automatically switches to track-and-monitor mode.
An interesting thing in the article: it says that testosterone levels drop for about the first six weeks so as to make us more "nurturing." I suppose that's true. While it's been highly--highly--irritating to be completely unable to do anything but care for the new one when I'm home (and too tired to be effective while at work), I've definitely been at least 37 percent more cuddly. But now we're at the 6-week mark, and just like that, the wife and I were able to have a whole conversation about finances while at the dinner table with all the kids around us.
I said to my wife through the din, astonished, "Honey, we just had a conversation."
Anyway, it's a good read. It's full of science and stuff.