Strange movie, actually. Love the series, read most of the books, was thinking to myself through most of the film that it is beautifully crafted and rendered.
That said...I was totally shocked when the credits came up. That was the end?!? The movie was just starting to get good!
The "big reveal" (i.e., who the half-blood prince actually is) and the "big fight scene" were both terribly under-whelming. The movie sputters and putters along, and then it ends...
A must-see for fans of the series and a vital set-up for the final two films, but not much else. Catch this one on cable between now and 2010 and 11, when the final installments arrive to the big screen.