I missed it in the theater (limited distribution in our area) and I was pretty pleased to find it on DVD so quickly since I thought I'd lost my chance to see it.
If you've read the book, you'll be surprised at some of the changes but I think you'll most likely still enjoy it. They weren't the most extreme changes I've ever seen in an adaptation (see "Flight of Dragons" for that), but it definitely wasn't the most faithful to the book either, which was a little disappointing since I liked the book so much.
This is the first Studio Ghibli production I've seen (I think The Hobbit was by the same artists, though, did anyone else have nightmares from that?), and while I was a little surprised at some of the imagery, overall it was pretty darn good.
I don't want to spoil anything, but I will say the romance is very sweet, and that the characters are very well characterized and engaging. Oh, and the Castle is really cool.
Oh, and the book was very good too.