Mainly popular science and for the curious, and just for general excellent discussions I see two of my favourite BBC shows are traveling across the pond. Firstly, QI is being shown on BBC America - starting from series* 'J' for some reason. Secondly, I've mentioned the Infinite Monkey Cage podcast a few times and I see they are doing some live shows, details here: http://www.infinitemonkeycage.com/
Anyhoo. Highly recommended, give them a try, and if you don't like it you don't have to watch or download anymore episodes.
*series=seasons, I believe.