Ask me again in 15 years...
Personally, I say Tiger has
already
established himself as the greatest ever. Nicklaus' 18 majors is just a number, signifying a longer period of greatness than Tiger can currently claim. But if TW never wins another major it will clearly be a result of injuries and personal issues, not shortcomings as a golfer, that caused him to fall shy of Jack's mark.
Tiger's achievements to date - including double-digit wins at the Masters and US Open -- surpass Jack's at the same period in their careers. And it's not like TW's only been around for a couple of years.
Tiger at his best was better than Jack at his best, primarily because TW's short game was MILES superior. And why is this argument based around one number only - 18? The other events count, too, and TW has already won almost as many total tourneys as Jack - not to mention one more US Amateur and three US Junior Ams.
Anyway, I realize there's an entire thread devoted to Tiger vs. Jack arguments. But hey, I've already posted there.
Cheers,
DoctorK