I've been looking at the Emerald Empire previews at AEG.
Interesting, altough it didn't made me want to buy the book. There's too much stuff there that is unlikely to fit my taste. I'm afraid they might have just reintroduced Dojo rules and Way of the Daimyo was a mixed bag for me, so I'm not that psyched about it being updated.
There's nothing hinting of vassal family content, either.
I was however pleasantly surprised by the preview of Enemies of the Empire. I had discounted it as being an expendable book, but the preview made me reconsider my opinion. I may very well come to buy it.