This looks like it’s the first of the post-season ARGs (alternate reality games).
There’s a message in Morse Code:
There’s a Twitter account, @simeonhobbes, which started sending out messages on Friday. At this moment, he has 2,035 followers, though I expect that number will increase dramatically as word gets out. The account has sent out mysterious messages, many of which mention Jacob.
Lostpedia has a lot more information.
Editing on 5/18 to add:
Twitter user Epithet Alpha is also in on it.
In addition to the main Lostpedia entry linked to above, check out the Lostpedia blog, which has more info and 127 comments so far.