Spoilers: Lost Season 6 Spoilers and Theories?

So the new season 6 of Lost starts today and this is the last season of Lost we will see.
After Season 6 there's no more Lost.
What are some spoilers and theories of Lost season 6?
Please post them below, I can't wait to find out what will happen on Lost in the next episodes. Also, are there spoilers about the actual ending of Lost? Does anyone know how Lost is going to end?
Please post theories, spoilers and the possible outcome of Lost. I want to know it all.
Been reading some spoilers and theories but I definitely need to read more.

The show has given us many surprises so far and I’m pretty sure will have many more in Season 6.

Been reading some interesting theories and spoilers about season 6.

I think Season 6 will open with the Losties having returned to their own time with the flash being the result of the wheel being turned by the gravitational force and not the bomb having gone off.

Maybe season 6 is going to explore convergent timeline theory. There are going to be three timelines running into one point, 1977 after the jughead detonation, 2004 where 815 never crashed (quite possibly the island was moved in the jughead detonation and therefore not where it was supposed to be when 815 crashed originally in ‘04), and 2007 after Jacob got killed.

There has already been fervent speculation about casting choices. Rumors abound that popular characters Charlie (Dominic Monaghan), Shannon (Maggie Grace), Boone (Ian Somerhalder) and Mr Eko (Adewale Akinnuoye-Agbaje) will be returning to the show.

I wonder what other theories are there about the ending of season 6.

Spoilers:

* Sawyer has the engagement ring he was planning on giving Juliet. He throws it into the ocean.
* There are many deaths in the first nine episodes. The Monster "wipes out a lot of people" and "does not like seamen."

I can't wait for the ending, been thinking about it since season one.
Spoilers for Season 6 of Lost:

* Harold Perrineau is coming back, but he has no idea what he’s doing. If he gets his wish, though, he’ll be telling Walt and Libby that he’s sorry.

* Speaking of Libby, that date that never happened between Hurley and the island’s resident shrink? Turns out it may finally take place, and this time they didn’t forget the blankets – OR the breath mints! Picture courtesy of Ryan Ozawa.

* "Locke" goes to the Barracks and brings Sawyer to a place with names and attached numbers. Locke's crossed out name is 4. Hurley's name is 8. Sawyer's name is 15. Sayid's name is 16. Jack's name is 23. Kwon (Jin or Sun) is 42. Kate's name is there as well. Jack and Hurley find a mirror at the lighthouse. It provides Jack a glimpse of his past when aligned correctly.

Post more theories please!