The UkeCast (as far as I can tell, the only podcast dedeicated to the Ukulele) is back with Episode 303. This podcast is hosted by Chris from the US and Nipper from the UK (you may have seen Nipper on a CNN article on the ukulele). Each episode features a mixture of music, news and uke-related information. This month’s UkeCast “features The Modesty Board, Ian Emerson, Yan Yalego, Howlin Hobbit and more!!!”
Check out the other archived UkeCast episodes at the site as well.
I don’t know if it counts as a podcast, but there are a ton of performance videos archived at Midnight Ukulele Disco, as well as a live feed. There’s also a web streaming version of Mary Martin’s Provincetown radio show (twice a month, all-ukulele), and that will be available as a podcast soon.