Update : it seems that Rhythmbox now has support for OPML import, you may type the path to the OPML import in the new feed dialog box. I didn't try it, though
I've just installed the brand new Ubuntu 9.04 to replace my good old 6.06, and now I must find a way to import all my podcast feeds exported in opml format from Juice, to Rhythmbox, the official Ubuntu music manager.
However, it seems that Rhythmbox does not manage opml imports. I don't feel like copying manually 70 rss feeds...
An opportunity to learn the XML library of Groovy !
Save this groovy script as opml2rhythmbox.groovy
Then if it is not already done, install Groovy
Execute the script on your exported opml file
Now, you must manually copy the content of the generated generated.xml file, into the ~/local/share/rhythmbox/rhythmdb.xml db file of Rhythmbox (make a backup of the rhythmdb.xml file before !)
The generated file content must be inserted after the rhythmdb opening tag at the begining of the rhythmdb.xml file
Then start Rhythmbox and run "Update all Feeds"
You're done !