Go ahead, buy it. You know you're curious. And people are prone to believe in conspiracy theories. This myth was first created in 1969 and has lived on ever since. Much like Paul McCartney himself. Just let me give you some antidotes to read after you've watched it. Here's the Wikipedia page on the Paul Is Dead myth. And here's an investigation by the rec.music.beatles news group.
The DVD is due out September 1st. Official movie site