Here is the way it went: They were supposed to have gotten married and the switch with the clone was supposed to happen AFTER they were married, etc., and in the end, Lois and Clark would have been married. The episodes were initially supposed to be:
#15 "It Happened All Night" (changed to "I Now Pronounce You")
#16 "Double Jeopardy"
#17 "Memory Lane" (changed to "Seconds")
Three episodes, no amnesia arc. So what happened?
Well, ABC was worried it would kill the show to have them married ... take away all of that UST and what do you have? Picket fences and baby names. So they figured they'd toy with the viewers a little longer, and initially wanted the entire arc (including amnesia) to be seven episodes. (Could you imagine?!?) It ended up being five. The irony is that by the time they finally did get married, the show was going down in flames, but for precisely the opposite reason as ABC had feared -- NOT letting them get married pissed off the viewers.
[insert words not acceptable on a family-friendly board] Even Dean said that the wedding had been pulled out from under them at the time, that they thought that Lois and Clark were going to be married right until the end.
Indications: In "It's a Small World After All," (episode #18; the first episode after the arc), Perry gives Lois a nameplate that says Lois Kent. Kind of an insensitive gift for someone whose wedding was busted up and had yet to reschedule, eh? And in "Through a Glass, Darkly," Lois comments that "us wacky Earth women get mighty cranky about losing our husbands." But they weren't married yet, right? Mmm hmm.
Allow me to point out that ABC also intially didn't want Lois to be told about Clark being Superman, but an impassioned fan campaign over the summer between Season 2 and Season 3 changed their minds.
