Orlando Bloom was practically 2 years into his film career when he did POTC and Kiera Knightley was an unknown (and she was under age at that). Granted, he was in LOTR, but he wasn't in much else before that.
		
		
	 
Regardless he was NOT unknown.  He had already co-starred in the biggest movies of 2001 and 2002.  He had a small role in Black Hawk Down.  By the time Pirates came out his posters covered the rooms of teenage girls everywhere.
Knightley wasn't as prolific as she is now but she was getting a ton of buzz off of BEND IT LIKE BECKHAM.
Geoffrey Rush and Johnny Depp were two established stars and veterans in the movie.  So no, it was hardly an UNKNOWN cast.  
Even though it was based on a ride, people were ready and hungry for a big swashbuckling pirate movie that was really good that hadn't been done well in years.  Pirates totally revived the genre.
	
	
		
		
			Also, I don't know what you mean by not valid comparisons. SW EP IV had unknowns in it. So did "Mad Max". Who knew about Leo DiCaprio or Kate Winslet before "Titanic"? These are valid comparisons.
		
		
	 
Harrison Ford was NOT unknown in Star Wars.  Peter Cushing was a well known actors' actor.  Among others.  Harrison Ford appeared in Lucas's AMERICAN GRAFFITTI which was a huge hit in the 70's.
Where the **** does Mad Max come from?  Mad Max wasn't some big surprise BO smash.  Nothing close, if anything it was more like a cool action cult film that yes did help establish Mel Gibson.  Mad Max wasn't what made Gibson a star or BO draw though, so you are definitely barking up the wrong tree.
	
	
		
		
			Mad Max  I am quite sure that you are not in on the planing so you can't possibly be a good judge on how it is being planned.
		
		
	 
What the hell does this mean?  
None of these are truly valid comparisons.  TITANIC was a huge movie and Cameron was a well known filmmaker whose career preceded him with the movie since his last movie was T2.  Leonardo DiCaprio was already an academy award nominated actor going into the movie.  He was an established heart throb after ROMEO AND JULIET which preceded Titanic and was a moderate hit for it's small budget.  Winslet was mostly an indie, British movie princess at the time, so that is all I will give you.
But at the end of the day, it's not really just working with an unknown cast.  It's about the cast being CREDIBLE and RIGHT FOR THE ROLES.  
	
	
		
		
			I think they are doing a pretty good job of it seeing that there is a writers strike and they have been able to get a (suposedly) "ready-to-shoot" script and are now setting up props for the film. It was even brilliant that the project more than likely categorized as an Australian film so that they can get the tax breaks from the Aussie goverment. I think you can only say that it was poorly planed when the actually fail at something and I don't see where any of that has happened.
		
		
	 
Obviously you thought wrong since WB has been getting extremely cold feet on the movie, and didn't make any of their planned or scheduled announcements that were promised.  They hacked and rushed to shoot a script put together right before the strike and reports indicate the script was far from READY TO SHOOT.
Judging from this paragraph you like to live in a fantasy world and don't know what you are talking about with movies.  It's not that simple.