The Talk Shows Sunday, August 21st, 2004 Guests to be interviewed today on major television talk shows: FOX NEWS SUNDAY (Fox Network): Van O'Dell of Swift Boat Veterans for Truth. MEET THE PRESS (NBC): Sen. George Allen, R-Va.; Sen. Jon Corzine, D-N.J.; Kerry campaign adviser Tad Devine; Bush campaign manager Ken Mehlman. FACE THE NATION (CBS): Sen. Pat Roberts, R-Kan; Sen. Carl Levin, D-Mich.; Democratic presidential nominee John Kerry's daughters, Vanessa and Alexandra. THIS WEEK (ABC): Former Clinton chief of staff John Podesta; John O'Neill of Swift Boat Veterans for Truth; Kerry economic adviser Gene Sperling; Rep. Rob Portman, R-Ohio....