I was really impressed with how easy it was to get up and running with RavenDB, and the query language was Linq directly. Even some of the other features he mentioned were great. Such as the automatic index creation based on your queries, meaning that your database speeds up over time instead of slowing down. The way Raven handles indexing is also interesting, instead of slowing down writes by updating all indexes on write, Raven updates the indexes asynchronously with Lucene!
All in all a great talk that I recommend watching.