Inside TWiT
TWiT on iTunes
Well it didn't last long - and I'm not surprised. The top podcasts are the ones that Apple features. However, you can still subscribe to TWiT via iTunes 4.9.
Under the Advanced menu select Subscribe to Podcast... and enter
http://feeds.feedburner.com/twit
It doesn't look like iTunes supports BitTorrent, alas, nor will it get podcasts when it's not running, so the best way to get TWiT for now is still using a podcasting client that does like iPodderX.