I found this presentation from Emil (Jan 19, 2010) much more informative than the podcast linked to from the release:

http://nosql.mypopescu.com/post/342947902/presentation-graph...

Edit:

What's really intriguing is what they're going to roll out with v2.0 - instead of basic, customer-written sharding algos, they're going to supply automatic sharding based on graph clustering algos.