rousseau died before they got rescued off the island by the freighter folks - so timeline wise, 2004 on the island. we are now 3 years later and in 2007. and she was buried. doesn't look like anybody buried is roaming the island...only those that died but the body is still out.
but it does look like claire has taken on the rousseau role as the one that set the traps and living in the woods.
which then leads to the question - was rousseau "infected" as well?
probably not...but she knew about the disease as she told sayid during season 1. then she also electrocuted him in a similar manner that dogun did in the temple. did she know how to test for the infection as well?
doesn't look too good for sawyer tho - he's in a position to be easily persuaded to join the MIB side.
i also noticed that all the folks the losties encounter in the alternate timeline were people that died on the island storyline: ethan, artz, boone, charlie, rose & bernard (who i think are dead). i wonder what the significance is.
another theory out there is that these are two seperate universes but the losties, which is why there is a charlie in one universe but a dead one in the other. and the deja-vu kate + jack sort of expierenced off the island are happening b/c both versions of them are starting to converge somehow.