I didn't think so.
According to the UK's Daily Mail, Depp will receive a massive payday in the form of $56 million US (aka 32 million pounds UK) to put on the black eye-liner for a fourth time.
Normally, I wouldn't believe this considering the source is the British tabloids which certainly are biased in the whole "truth-telling" department. That said, there's probably something to this news item.
Say what you will about their quality (God knows I've said my fair share... and then some!), both Pirates sequels chugged out just under $2 billion between them. And that doesn't even include the big-bucks the Mouse earned from home video sales, television rights, merchandising, etc.
No two ways around it, Depp is the franchise. Like Harrison Ford with Indiana Jones, this isn't a film series where the actor is interchangeable to the character (like James Bond and Superman to name a few) and Disney is smart enough to realize that.
And from the sounds of things, the studio wanted to make damned sure they had Depp lined up before hiring anyone else. Thus why they've yet to hire screenwriter(s) or a director - at least that we know of at the moment.
Pirates of the Caribbean 4 is currently aiming for a May 2011 release.
Source: The Daily Mail