Will this be the last POTC movie?

Depends on how much $$$ it makes.

I'm sure I read Depp was contracted for 6 PotC films

I doubt it. There will probably be a sixth film to round out the saga as two trilogies. Similar to how the first six Star Wars films were two trilogies.

I think there will be another one so they can market it as two two trilogies, like the other poster mentioned. And then of course they'll probably make a bunch more of these things in low budget mode without the original cast. Skip theatrical release all together.

"I said no camels, that's five camels, can't you count?"

I doubt this will be the last film. And knowing Johnny Depp and Disney, they'll milk this cash cow until it's dry.
I suspect a sixth movie coming our way to make 4, 5, and 6 a trilogy.

If this makes enough money, you can bet your ass they'll make a 6th one.

What's missing in movies is same as in society: a good sense of work ethic and living up to ideals.

Ever since the last one came out, I've been assuming that 5 would be the last. But I guess I could see another one being made after this.

The legend of the dog faced woman.

These movies are going to last as long as Depp is still willing to play Jack Sparrow or until he dies.