OK, first of all this is purely my opinion and some sources from wrestler's mouths themselves.
Now, what if Vince died tomorrow...or retired from the business, would he give the business to HHH, Stephanie, Shane? Would his wish be he purchased TNA before he died? Now disregard both of the rubbish contenders HHH and Stephanie, and lets talk about the legend that is Shane McMahon.
Shane McMahon went to college, graduated, and went straight into the family business. The guy had little input into story lines when he was young, and wrestled part time for the company. He went out, and gave it his all.
He once said that if the wrestlers are going to be doing high spots, then he would also do it to see how scary and hurtful it is to do them spots. Thus, he fell off the titantron, electrocuted his balls and done an elbow drop off the rafters. The wrestlers loved him as he was one of the boys, even though he was higher up than them, and he would never let the wrestlers do what he won't do himself.
Now, imagine him as the boss. I can see him changing it all around, because he is a people's person, he would give the fans what they want to see. He will give the fans what they PAY to see. Good action and wrestlers that actually need a push, given a push. There would be more action, and not that PG action we see today. His Feud with Vince at Wrestlemania 17 was no way corny, and one of the most memorable matches in history, and this is only because Shane knew what to do and what the fans would like to see.
Shane McMahon is a great leader, and one day he shall be a great promoter who shall see TNA as a competitor, but will not blatantly try to put it out of business, and shall follow on from his grandfather's footstep rather than Vince "Satan Himself" McMahon.