In today's modern world I believe that it is imperative that the public have the right to see that criminal trials are televised, subject to prior court approval, proper decorum, and the rule of law. Transparency is a net benefit to society at large and is an important foundation when interacting with public servants. By law, our trials are public trials and what better way to present trials in today's world but by television. Although I cite television as my preferred mode of viewing, I would also be a proponent of a radio broadcast, podcast, or even updates via twitter or similar. I do believe that it's important to present criminal trials to the viewing public utilizing media that is cost-effective, prevalent, relevant, flexible, and easily affordable.
Having criminal trials available to the public will help to get the public more engaged in our overall criminal justice system in which most citizens are willfully ignorant of. It's common to have City Council meetings televised, so it certainly isn't much of a stretch to be able to provide certain criminal trials in the same type of format. Criminal trials need not be shown "live", they could be tape delayed, edited, or the such, as long as the interests of the public are served and kept foremost in mind than the results should echo those facts. Therefore if there was a particular concern, for instance that the televising of a certain case might influence the jury in some way, form, or manner, the trial broadcast could be delayed until a verdict had been reached. While that would certainly take away from the day-to-day drama because the case outcome would now be known, it would still attract interest from the general public, especially "armchair quarterbacks" and those that just have a certain fascination with trials that pique their interests.
Another segment of the population that would definitely have a vested interest in current criminal trial broadcasts would be lawyers, or law students, or the like. Using broadcast criminal trial media, you would be able to get past the theory and get into particulars. Debates between students or students and their Professor could be done in 'real-time' and would be very practical given the circumstances of their profession or professed profession. In theory, the watching of real trials may whet certain students' interests, or for some, it might put them off and perhaps they would re-evaluate their life goals and direction. The real world is not the same as something that you picture in your mind, or read in a book; the real worlds' nuances and drama are something that must be experienced in order to appreciate and comprehend.
Additionally, court cases and trials are a practical example of your tax dollars being put to work and importantly the application of constitutional principles in our everyday life. The public has not just the right to know but the need to know and therefore should have access to know. The barrier to entry to present criminal trials in some sort of media format has never been lower than it is today and therefore this is another valid reason as to why these trials and their availability must be a choice that informed citizens can avail themselves of.