I also don't like the idea of deathbed repentance, but I suppose I should say that in my version of events Vader isn't a child murderer, at the very least. Just as Mr. Plinkett preferred, most of the actions he performs are as an enforcer, on the orders of someone else - Tarkin, the Emperor, whoever. This doesn't excuse his actions, but it makes the idea of redemption more palatable. It should be kept in mind how things felt before the prequels altered it.
A potential compromise:
http://www.youtube.com/watch?v=h0EqJjUPbLs&list=FLvRjv9hKkiQDztlyqbymhHg&index=68&feature=plpp_video