I can't answer your question directly, however, I can tell you that we vacationed at WDW during the thrid week of March last year and on average the wait time for the regular line was around 30 minutes. By making use of the Fast Pass system we were able to see just about everything.
We are returning again this year during the thiird week of March and hopefully will encounter the same as last year. One side note is that there will be a dance and cheerleading competition during the weekend of March 13/14, this was the same as last year and although the crowds weren't effected, it would be wise to prepare yourself to be surounded by a potentially large and loud group of girls.