Yes, I think it is a great idea providing JC content is defined and planned in advance (so that interested people can reserve some time). Maybe we could start with focused topics based on recent posts (where diverging opinions were expressed, or with large voting rate on Q or A), or more general ones (no idea about that), or users might suggest some topics based on recent literature/work that will be submitted to a voting process (JC participants or CV users).
I have no idea of a time that would best fit with everyone's agenda. It seems, however, that most users are somewhere between US and Europe (I must apologize for extrapolating this way), so 5pm in NYC means 11pm in France/Germany (a little bit late). So I guess we have to find a compromise, e.g. 1 or 2pm US time?
About frequency, what is your idea? I won't expect a great audience on a daily basis, but maybe every 2 weeks or every month will be a reasonable starting point.