Well, I’ve heard basically nothing about this – it’s not even listed on the Internet Movie Database – But in my reading, I did run across This (click that) which seems to say that they’re planning a 3rd Pirates of the Caribbean movie and pulling off a “Matrix sequels”-type of release format – with parts 2 and 3 filmed at the same time and being released 6 months apart from each other in the same year.
The other notable being that this page has Keith Richards listed in the cast. I had heard Johnny Depp wanted him in the sequel(s), but hadn’t heard anything concrete. This report is probably fairly sketchy at best so far. At least we can blame someone else if it’s wrong.