My "hunch" is that to ridgidly divide the two worlds is to somehow defy the nature of network connections while trying to control something that cannot be controlled. The web of network connections of which I'm a part cannot be controlled by me (or any individual). The only person I can control is myself; it is therefore up to me to present myself - personally and professionally - in a way that makes me feel proud and genuine.
As we become more aware of the power of our digital footprint and as network connections evolve in complexity, I feel that we will move away from keeping separate "lives" and trying to control what certain people see or don't see. We will begin to present ourselves more holistically (rather than severed parcels) and make sophisticated choices about what we choose to share. The result: our personal presentation of ourself becomes more professional; our professional presentation becomes more personal.