Well! This was very interesting. Assuming I haven't made any dumb errors, there is one bug in ColdFusion 8 and three in ColdFusion 9 within the listToArray() function. The following is a MXUnit test case illustrating what I believe is expected, given the way the documentation defines the function:

Here are the test results when executed in ColdFusion 8. Note that when an empty string is passed to the function, and the "include empty fields" flag is turned on, the function creates an array element, even though there were no delimiters between which an empty field could exist.

When the same test is run in ColdFusion 9, the behavior from ColdFusion 8 is mimicked with regard to an empty input. However, when creating an array based on input of a single space, the results differ -- ColdFusion 9 effectively ignores the character unless the "include empty fields" is enabled.

Thanks to Ben for suggesting that I dig deeper. The oddity in ColdFusion 8 has probably been known for a while, although I hadn't encountered it before. The issue with ColdFusion 9 doesn't seem to have been mentioned on the interwebs. It's not in the Adobe bug database, that I can find.