Originally Posted by
bat39
Lana was basically created to be Lois for the Superboy stories, since as fast and loose as those early stories played with continuity, even they wouldn't go so far as to backport Lois into Clark's teenage years! Later continuities and adaptations have worked with this blank slate and fleshed her out, notably by making her Clark's first confidant outside of the Kents and even by teasing the possibility of a relationship when they reunite as adults.
I'm not really sure there's much of a 'problem' here though. Clark was in love with one woman who he grew up with. But, like many other men, he left his hometown, put down roots in another place, and fell in love with a woman from his new life. Not really sure what's complicated about that!
I haven't watched a lot of Smallville so I dunno how they handled it there, but Byrne kinda made Clark's reunion with Lana in MOS # 6 a teachable moment for him, where he briefly reflects on what he lost when he left Lana and Smallville behind, but then resolves to do something concrete about his growing feelings for Lois. I feel if you want the 'transition' to have some kind of impact, that's the best way to do it - Clark realizing the importance of life beyond Superman in what he lost with Lana, and resolving not to make that mistake with Lois.