I think the current format of 3 beginner lessons, 1 intermediate, 1 survival lesson, 1 cultural and 1 news/rest day is a good balance for a website teaching *beginner* Japanese.
The 3 beginner and 1 survival lessons form the core of the program from which I learn the most, and the culture class opens my eyes to a very different world. However, the intermediate lesson is the least useful of the lessons as I often find myself lost just 5 minutes into those. As for the news, I only chime in if I miss the voices of the jpod crew that much.
Ultimately, the target audience for Jpod101 are the beginners with little or no experience with the Japanese language; hence, the site-name: JPod101.com.
Your suggestion would make a ratio of 3:2 for beginning (and survival)-to-intermediate lessons. That would make jpod101.com ambiguous as to who their target audience is. It could end up having the beginners tuning in half the week and the intermediate listeners the other half. Both groups would feel like they're getting only half the benefits and would probably leave for other sites that can give them a fuller experience. That would make one *bad* business model.
In fact, I would prefer to have *less* of the intermediate lessons, like every *other* week instead.