I'm also one of the persons who are desperately waiting for the white iPhone 4.
To be honest I really don't know what to believe at the moment.
Problems with the colors may be a quite serious problem for Apple, if this problem ever was existent, but there are some repair stores who are selling white parts and in my opinion I've never seen outstanding mismatched parts. And - four months for fixing a problem regarding color? I don't think so.
For me there are some possibilities:
1) The white iPhone 4 is delayed because Apple needs to produce enough of the black ones to calm most of the people ("black is more popular") and will release the white iPhone afterwards. And there may be some, or even many, people who are waiting for the white one - but most of the people don't care so much about the color and just buy the black one. In the end I feel quite weird that I wait so long only for a color, sometimes..
I've had the black one just at the beginning (with a contract) but experiencing the antenna issues, I was disappointed and on top I was having an expensive two year contract. When I read how to get a cheap and "Lock-free" iPhone from UK I just returned the black iPhone 4 and thought: "Okay, so now you can also wait for the sexy white one, too."
2) Apple is working on another, modified version of the iPhone 4 (antenna fix, new features, CDMA, whatever..) and will release this version along with the white one.
3) The white one is cancelled.
I just hope Apple will release it this year. Because of Christmas it is quite possible.. Christmas presents = $$$
But who knows.