I admit, the second season`s finale of LOST was amazing. I was a bit disappointed from the last episodes but this one absolutely turned my interest back. Finally, something really important happened and we found out some of the Island`s secrets and as it seems – we`ll continue to figure them out in the next season.
There`s obviously no sickness on the Island and maybe the sign “quarantine” on the doors just have to keep the people in the hatches so that they continue to do their job about the experiment of Dharma Project. That doesn`t explain why Russo has killed her friends, thinking they were “sick”, but probably she just got crazy (which actually doesn`t seem very likely) or maybe there is something more that we still don`t know.
Michael seems to be one of the most stupid characters but I don`t think that this is the end of his appearance. Walt has some paranormal abilities that have to be shown. I think that Michael and Walt either will decide to come back (because of Michael`s consciousness) or won`t be able to find the way and finally the ocean will bring them back to the Island.
About the Others, I don`t think they will hurt Kate, Jack and Sawyer. They will probably use them for their experiments or try to make them a part of their group. Which is more interesting for me is why do the Others hide their identity? Who are they hiding from?! That`s something that I really can`t wait to find out.