Okay... I've been trying to figure out a way to post this and can't come up with an elegant solution. Here goes.
The following comments are intended to be taken as "tongue-in-cheek." The do not reflect my actual interpretation of the finale of LOST. These comments are merely spawned from my own sick and twisted sense of humor.
MIB WON. Remember when MIB told Jack that HE was Christian the WHOLE TIME? Well, at the end of the season finale, the Christian Shepherd that appeared to Jack was the Man in Black once again! Everything he told Jack about the afterlife was a complete lie. He had convinced the survivors that they were "moving on" when in fact they were all just committing suicide and giving MIB what he wanted.
See. Told you it was sick and twisted :)