Will & Grace is back with new episodes, and a Roseanne revival is set to premiere next month. Plus, there are rumors of a Seinfeld reboot. Fans of these shows are excited about them returning to their screens. So why do we love seeing specific characters and shows back on TV after years off the air? Our guests talk about nostalgia, and what the teams behind the revival shows need to do to keep their audiences watching. In studio: Bob Thompson , director of the Bleier Center for Television