Personally, I like NPR's Marketplace a lot... But, my interest in TTD is to discover new shows.
So, my suggestion would be to do something similar to WTD; try to walk every talk show out there, in the hope that it will allow some TTD followers to discover new shows they didn't know about.
Now, it is unrealistic to do this with every talk show on Sirius/XM, sat/online, usa/cdn. So, I would try, as much as possible, to limit shows to those available to both Sirius and XM USA satellite subscribers (without BestOf).
We could rule out some categories of shows, or, alternately, determine three or four broad categories (e.g. religion, sports, adult, other) and publish TTD threads in all these categories at once. This would allow people not interested in some category to still have something to listen to.