Here are a couple of more links you should look at:
Article by Don Marti:
Podcast on it:
Don introduced it to me a little while ago. Personally I am pretty excited to see this work being done.
Now will someone please deliver a Map/Reduce system written in either C or Python? I have a big preference for it to be C.
(My other option for a Map/Reduce system is to cobble together some Danga technology and see what I can put together).