From what I have read if they remarry then there will be a very strict contract with a cheating clause as well, so if Elin Nordegren believes she can trust Tiger Woods and she is still in love with him then she should remarry him as it seems she has covered all her bases in case of another scandal. Ultimately she needs to do what she wants and follow her heart, regardless of what the public may think.
There is no reasonable person that could honestly think that Elin Nordegren should marry Tiger Woods a second time. He didn't exactly set the world on fire with trustworthiness their first time being married. I'm sure she received an excellent settlement after their divorce, so there isn't even a financial incentive to remarry.
Tiger Woods is not a changed man. He cheated on her with so many women. It was clearly not an isolated event. It was a way of life for him. He is rich and famous and can have anything he wants. I would find it very difficult, or impossible, to ever trust him again.
Elin Nordegren should not remarry Tiger Woods. Her image has been shattered and getting back with Woods would not be a good this. He cheated on her numerous times and there's no reason to believe he would not do it again. She needs to just move on with her life.