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From the PDGA Website :
All PDGA officials will need to be recertified in 2011 and every three years thereafter. A new online rules official exam will be launched and tournament directors of sanctioned events will be given a complimentary exam. All pro players competing in a National Tour Elite Series event or Major will be required to take and pass the new rules official exam.
The Unplayable Lie rule has been renamed the Optional Rethrow rule. You will be able to call a rethrow with a 1-shot penalty after any shot you throw whether it lands in a penalty location (OB, missed mando, above 2m) or inbounds. Player's choice. Group has no say in the matter.
Thats how I understand it.
So if you throw a horrible shot off the tee pad and want to, you can "Tin Cup" it and re throw.. with a one stroke penalty each time of course.
Only advantage I see is that it may speed up play during tournaments. In casual play you should take the rough shot. If you always just rethrow, you'll never get good at getting out of trouble.