no offense taken. What makes this episode unusual is that Eko may have been the first character (maybe Locke too?) to resolve his guilt and to forgive himself. This is in stark contrast to Charlie, who can not forgive himself, and is in fact "literally" storing and building-up his guilt (hiding of the statues).
The question for me is, what is the black cloud? Is it a real phenomena? Is it metaphysical? Or, are all the people on the island in a "matrix" type atmosphere where they are placed in a virtual world to face their demons - or experimented on? Therefore, everything is virtual - but real, in that the thoughts of an individual can be seen by others. The subjective becoming objective - a F'ed up group therapy?
This goes back to my play on John Locke's name. As we discussed before, John Locke, the philosopher, was an "idealist," meaning that reality is what is perceived. What if the subjective nature of Lockean reality becomes objective - i.e., everyone experiences eathother's thoughts and can manipulate them. Maybe that is why Walt had to be removed - he could manipulate other's reality (make things happen) too easily and screw up the whole process.
Or, as I said before, this may all be one big F'ed up reality show with unwitting and unwilling participants.