Creators Miles Millar and Al Gough confirmed on the TalkVille podcast that prior to Erica Durance's casting, the possibility existed.
WBTV
Smallville: How an Alternate Lois Lane Was Discussed
"We did talk about that, that maybe [Chloe] is the proto-Lois and that later on she had to change her identity or something like that, and she becomes Lois[...]
