First up is Caesar, a dangerous, physical and extremely intelligent male between the ages of 35 and 45. Although his intentions are unclear, this much is certain: He's as skillful at charming people as he is at killing them. He also has a dark past, but, c'mon, that much was a given.
The other newbie is Ilanna, a European female in her late 20s to early 30s who possesses great intelligence, but who's also dangerous as all get out. She's alluring and apparently used to getting her own way.
The site mentions that these will be recurring characters in the fifth season with the possibility of being upgraded to series regulars for the sixth and final season. Casting for the roles is currently under way.
Lost will return with its fifth season in February 2009.