Cenk Uygur has a post about the latest version of the traditional Meet the Press "journalists plus conservatives" roundtable. Aside from the perpetual lack of liberal voices on these things, which is of course an issue, I don't understand why journalists agree to appear on these things (and why their editors allow them to).
Journalists are limited in the range of "opinion" they're allowed to express on these things. Essentially, they are allowed to regurgitate current conventional wisdom or offer up "liberals say..." or "conservatives say..." type of sentences. They're placed in a conversation with partisan hacks, who are not constrained by anything at all. Even if there was an actual liberal on for balance I would still object to journalists appearing in these formats.