This hinges alot on the 'idea' that Michael is the man in the coffin..
In 4.08 - Meet Kevin Johnson, Michael (in his flashback) sold the watch that Jin gave him.
We know that at somepoint Jin dies (least that's the suggestion), most likely before the Oceanic 6 get back home.
I think that Michael
selling Jin's watch may be a little clue to the possibility that Michael
sells out again, on his return to the island - more specifically, he may be the one responsible for the
'death' of Jin. Jin wouldn't be the first island father to be killed - if the
'is Alex pregnant?' suggestions are true.
This (and other events) would possibly explain Kate's unwillingness to attend his funeral - as I don't believe Kate would be so unwilling to attend his funeral for his initial act in saving his son and leaving the island. There has to be something more..a repeated trangresion perhaps.. to make her of all people so disgusted by him as to not attend his funeral.
Again, this relies largely on the idea that Mike is the man in the coffin (personally I still think it's more likely to be Ben or Locke, but I want to put this idea out there).
All in all I have a feeling that Michael doesn't get to redeem himself.
On a side note, I find it interesting how Mike tried to redeem his freewill via the sale of Jin's watch for the gun (to kill himself), yet redemption still seems so far away.
Not much of a theory at the moment, but as always I hope to flesh it out of the course of time, if only for my own curiousity in the direction of the story.