A bunch of folks have been asking about non-iTunes feeds for TNT. They exist and will be posted on http://twit.tv/tnt as soon as possible.
Here are a few of them in case you want them early:
Video:
http://feeds.twit.tv/tnt_video_large
http://feeds.twit.tv/tnt_video_small
Audio:
http://leoville.tv/podcasts/tnt or http://leo.am/podcasts/tnt