Hold all thoughts for a moment.
Vicki: 
Yay! A dissenter! I was looking for one of you... that's why I said it "seems" we are all in agreement (I, of course, enjoy playing the role of devil's advocate, so Clark not telling her works out just fine by me). I think you draw attention to an interesting point-- Clark was never there to see Lois' pain. If he *had* seen it, then I agree that he should have come out and told her the truth (well, even that can be circumstantial-- depending on how he comes about seeing her). But the crucial part is that he didn't and that changes everything.
I agree that he should have told her probably by WWW. But think about it this way: if the secret wasn't about something positive, such as Clark being Superman, and instead was about Clark being wanted for murder (I'm talking in the extremes here), would you still wait to tell? What makes it okay for Clark to wait so long before telling Lois the truth? The dual identity (in which case, the argument of "I want her to love me for me, not just the escaped convict version of me" does not apply)? The fact that it's sort of a good secret, and not a bad one? Where's the line?
