From what I can tell, most of them aren't unique until we get to the alarms - a few of them are brand new based on my Google searches:
- Fermium.ogg [audio:ics/alarms/Fermium.mp3]
- Hassium.ogg [audio:ics/alarms/Hassium.mp3]
- Neptunium.ogg [audio:ics/alarms/Neptunium.mp3]
- Nobelium.ogg [audio:ics/alarms/Nobelium.mp3]
The alarm sounds are quite futuristic and magical, instantly reminding me of Tron. Considering Honeycomb already started in this direction and ICS' theme is also Tron-like blue, I think we'll be hearing and seeing a lot more audio and visuals in a similar style.
As per P3Droid's request, we're not going to post the download link to Nexus_Audio.zip and instead direct you to this MyDroidWorld post (registration required to download). Enjoy!
P.S. That thumb looks delicious, doesn't it?