Some recommend to reverse your front and rear brakes (so that the left lever operates the rear). But in my short career as a cyclocrosser (2 races) I haven't really had problems with the regular setup. I believe I am pretty good at modulating the front, and as you know from motorized vehicles, the front brake is your best friend (it's more effective and doesn't skid as easily...when your rear wheel(s) lose grip, then you're really in trouble). Plus it is safer if all my bikes are the same. Plus, I don't think Simon Burney mentions anything about reversing the brakes.
What percentage of top crossers go reversed? What decides their preference? What do you do, and why?