Lightroom is designed for working with multiple images efficiently, Photoshop is designed for working intensely with single images. Pretty sure those design principles will continue down those relatively divergent paths.
From the above quote it makes me think that a common pro photographer will need both PS and LR,
As a common pro photographer,in some assignments you may land up in processing large number images in shortest possible amount time with best possible quality with the above time constraint, in that case you need LR.
And the same pro photographer in some other assignment may land up in the situation of intensely tweaking very few images, in that case he needs to fall back on PS.
So, the moral of the story is YOU need both LR and PS, as of now! or may be forever !!!
and the simple trick is choosing the right tool and right work flow for the job at hand.