Brian,
One way to achieve nearly the next best thing to a senior person from your profession is to ask one or more recent graduates who are working to come and speak. What they lack in experience they more than make up for in enthusiasm, familiarity with your program and it's classes, and experiences they may had that are interesting and attractive to current students. Often, student are more willing to ask pointed questions to "one of their peer group" than they might of "an outsider".
Barry Westling