In terms of sheer entertainment value, it looks like an appropriately fun time-killer. In terms of it being a general good movie, my reaction would be a resounding 'Meh' or 'Doubtful at best'.
Negative points: I can't see how this is going to be any different from the second and third movies (which, although I still personally liked, travelled down into silliness and cliche, and generally suffered from a bad case of sequelitis). Plus points: this film seems to have more pirates in it, and considering it's meant to be a movie about, you know, pirates, this seems like a good thing. Also, no Orlando Bloom, which I couldn't be happier about. I never minded Keira Knightley, but he truly ruined every single movie for me, especially the first.
But it has Johnny Depp and Geoffrey Rush in it, meaning I will see it at least thirty times. <3