Select Podcasts, then File > Export Song List
The output is kind of ugly.
Or you could use a little AppleScript I just wrote (paste it into Script Editor):
Code:
tell application "iTunes"
set pcasts to playlist "Podcasts"
set s to ""
repeat with t in every track of pcasts
set s to s & name of t & "
"
end repeat
end tell
For Windows, the script won't work (obviously).