The show is called Haunted and it's a short-lived series Matthew Fox did before Lost. Sci-Fi is resurrecting it and running it in Lost's timeslot on Wednesday nights.
As for the end of Lost...the show only has 3 more short seasons left.
The normal run for a season of a show is 24 episodes. They will be doing 48 more episodes of Lost (basically 2 seasons), but they are splitting it into 3 16-episode seasons.
The first of these 3 will begin in January '08. Also...they're waiting until January to air Lost so they can do it uninterrupted, like 24. Instead of running 6 shows, taking a 2 month break and then finishing the season.
Jim