This is a subject of more than ample debate among motorcyclist around the world. I don't know that I have strong opinion about the subject, as I don't know that I would personally feel comfortable doing it on a regular basis. Of course, I don't actually spend much time on roads where it is relevant, but the few times I have found myself in a situation where it would be appropriate, I have to admit that I would like the privilege.
I think what bothers me about the whole thing is that as a rule, drivers don't get it, though they do it all the time. I've lost count of the number of times I'll be first at a red light and have a car squeeze past me on the right to turn right on red. Under Georgia law, this is failure to yield and they are clearly in the wrong, but is commonly practiced and largely not enforced. Meanwhile, if I were to 'filter' forward past them for the same reasons, the same drivers get angry and antagonistic.
The same holds true of lane sharing or 'whitelining' in traffic. It makes sense, and as a rider, the safety of moving forward, not sitting in a position where it is like inviting a rear end accident. I am convinced that if most drivers could, they would. Look at the number of them ducking and weaving in traffic as it is.
In the environment today, lane sharing is explicitly illegal in Georgia there is no grey area like there is in California.
Yet, when contacting my state reps about the issue, I'm told that they are listening to ABATE on these issues. So I take a look at ABATE. The concern is helmet laws, they want them removed from the books or altered to make them not required, when it comes to lane sharing, they have no interest.
So while I would love to see change, it is clear that there is not enough interest yet.
Perhaps that is not a bad thing, but it would seem that as bad as Georgia traffic is, there would be pressure to find ways to ease the congestion which is now worse than even Los Angeles.