All this could be avoided if only applicants were better able gauge their own English proficiency and interpret that against the requirements of the school. As a first step towards realizing this, I've gathered together a number of free online and downloadable tests that vary in their length, accuracy, and feedback. Individually, each can give international students some hint about their level, and, when taken together, are likely to give candidates quite a good picture of their proficiency.
The next step is now to begin to calibrate the tests against our own entrance requirements. It should prove to be an interesting project.
And of course, there is no intention whatsoever to use these for high stakes purposes. They are intended only as a tool to help international students plan their time here before they come over and are seriously disappointed.
I'd like to thank Russell Kent, Jim Purpura, Glen Fulcher, and the other folks from the L-Test mailing list who offered ideas.