So far no MAIN characters have been offed. Ana-Lucia, Eko, etc. were all peripheral. The MAIN characters seem to be Jack, Kate, Sawyer, and Locke (but I'm still debating with myself about Locke). I doubt very much if any of them buy the farm this season. We have not seen Bernard, and both Nikki and Paulo seem to be playing the star trek "Red Shirt" role. The two new characters would be my best guess right now seeing as how the creators/writers/producers are trek-fans, the Red Shirts are the logical choice

"Paolo" is in discussion right now to negotiate his contract for 3, yes you read it right, THREE years--which blows the promise to keep the show to 5 years.
Anyone smell a shark jumping overhead?
cheers
*Des8