Cupcake was a branch in Googles SVN (or whatever they use) that they've now merged back into the trunk, so you don't "get cupcake", you just install Android.

XTerm won't continue to play your Sirius, because:

1. A terminal emulator doesn't play internet radio very well in any case.
2. There is no xterm for Android (I think).
3. Whatever program you are running from your osso-xterm in all probability would not work on Android even if it did have an xterm, because there are no sound drivers for the Nitdroid kernel.