When was the whole "fire incident" mid-80's IIRC...
First off the whole image of Michael Jackson would be entirely different, a thriving pop-star cut down in his prime. His funeral would be a pop-culture and media circus that's for sure...
The world is also sparred the travesties of his later records...probably making MJ less of a joke in the musical world.
I'd also imagine that a fair number of tribute bands might emerge from the woodwork...Perhaps an Elvis like cult develops (albeit on a smaller scale?) Perhaps the other Jackson kids' careers get a boost from their brother's untimely demise...