The conference Be[comi]ng Dutch has posted a number of great videos, including ones with Mouffe and Spivak.

Link

Jodi Dean has a number of posts on Laclau and Copjec

I have reviewed Ernesto Laclau’s On Populist Reason for the inaugural issue of Expositions.

Link to the review

From Alex D, a terrific site:

http://www.discoursenotebook.com

There are public lectures by Badiou, Kristeva, Mouffe, Critchley, Zizek, etc.  

Just in case your institution does not subscribe to it, you can freely access the March 2006 issue of Constellations: An International Journal of Critical and Democratic Theory. Just a sample:

• “Paradoxes of Capitalism” (Martin Hartmann, Axel Honneth)
• “Resurrecting the Rationality” of Ideology Critique: Reflections on Laclau on Ideology” (Maeve Cooke)
• “From Critical Social Theory to a Social Theory of Critique: On the Critique of Ideology after the Pragmatic Turn” (Robin Celikates)

[As constellations go, so do important birthdays - happy birthday to C]