Lost Prehash - Speculation Without Spoilers

I have high expectations for tonight's episode (which should be obvious since I'm pre-blogging). It's the episode where we learn about Ben's past and perhaps the origins of the Others. More importantly, we've been promised that we'll learn who Jacob is, and Locke will hear two words that will radically change his view of the island.

The speculation has been crazy so far. Jacob is:

• Jack
• A doll
• Richard
• The Smoke Monster
• Joop the Orangutan
• Vincent the dog
• A figment of Ben's imagination
• Locke

Anyway, you can pretty much go anywhere with this stuff. For me, the most likely answer will be one that leads to the big showdown between Jack and Locke that is supposed to happen in the finale.