I would certainly give it a shot as well. I love listening to D&D podcasts on the way to and from work. I agree completely with Crothian's recommendations, and I add that you should write it out before taping it. What emerges from unscripted dialogue is almost never interesting, unless the individuals are extremely talented professionals.
I would recommend against having it completely scripted, but until the hosts are experienced enough to be able to do it from the bare minimum of an outline, I would definitely go with a very well-detailed outline.