Eh, I think this idea that we must live our whole life in public (to the /same/ public using the /same/ identity) is a bit insidious. Especially in these days of "cultural fit" - it leads to this idea that you need to spend your private life in service of your professional life.
If you have an unpopular hobby or sexual proclivity, keeping that out of your professional life, in many circles, could be even seen as polite; At the office? nobody wants to know about your love for furry fan-fiction.
Sure, cute cat videos are different from furry fan fiction, but... if I'm "following" you? I will "unfollow" if there are a bunch of cute cat videos. I mean, unless I'm following you for your great taste in cute cat videos. More to the point, if I'm evaluating you and, say, your long screeds advocating a political cause I find particularly distasteful keep coming up, I might have a hard time evaluating you rationally, on your skills. (Also, if I'm hiring you, I want you to be able to leave the bullshit at home. Leaving the bullshit in another identity helps with that sort of thing.)
I really think that multiple identities is the solution. You can have your cute cat picture identity, your furry fan-fiction identity, your radical socialist identity, and your professional programmer identity. I can choose to follow the identity I find interesting. I mean, yeah, if someone /really wants/ to connect your furry fan-fiction identity to your professional programmer identity, they can. However, if you practice proper identity hygiene, it becomes much easier for me (or another third party) to interact with the professional programmer, without dealing with your hobbies I have no interest in, or maybe even find distasteful.
Most of the "real name" folks seem to think that by making everything public, we will see that we are all weirdos, and become more accepting of our differences.
I guess that's my prime problem with the 'real name' folks; I think that it's just fine to do business with, or even relate socially to folks that have hobbies or political views that I believe are downright wrong. I don't think that 'acceptance' is required for that. I think that you can like and trust one facet of a person's personality, without liking other facets of their personality.
I want to be able to say "I think this person is a great programmer" without implying that I also endorse their badly written Spock/Kirk slash fiction, or their half-baked anarcho-capitalist political rants.
My point is that I may have 'cat video friends' who, you know, are in to that sort of thing, with whom I may wish to share these sorts of things.
My point is that while it's fine to have my cat video friends, I ought to have the option of not sharing my 'cat fancy' with other groups who may look down on that sort of thing.
Personally I'm a big fan of encouraging the use of real identities for reputation management in online communities instead of relying on fake Internet points. We'll have to wait and see how it all shakes down!
For me personally? I use my real name for most things. It's convenient. And in a "cultural fit" world, well, I am a "cultural fit" for my profession, so why not run with it? Nearly everything I've done online in the last decade has been under my real name.
That's the key, though. Being a 'cultural fit' means that the community is unlikely to have a problem with my personal life, and if they do, it's likely to be a minor sort of thing.
Edit: forgot to mention, you have to explicitly connect the G+ Page to YouTube.