Podcasting support is in the works for Thunderbird, Mozilla's open-source email client.
According to Mozilla's Thunderbird 2.0 Roadmap, podcast support is to be added in the 1.1 release, scheduled for late June 2005.
1.1 Goals
* Inline spell checking
* Improved spell check engine.
* Deleting attachments from e-mail
* Auto Save As Draft
* Phishing Detector
* Improved RSS Support including new subscriptions UI, OPML import, and podcasting
* Software Auto Update
* Options dialog re-organization
* Improved integration with anti-virus applications for POP3 users
* Improved UI for managing SMTP servers
* Support forward and reply from message filters
Podcasting support is in the works for Thunderbird, Mozilla's open-source email client. 
