I think I may have missed that thread. Thanks for the head's up.
Magic Origins is the summer expansion. MM2 fills the Commander/Planechase/etc. space.
Nope. Among the players in tournaments that decide what Wizards thinks of the metagame, Tarmogoyf's price is a non-factor. And while Tarmogoyf is a great card, it is not the best card for all possible decks. If you're attacking with creatures and running Green, Tarmogoyf is pretty good. If you're trying to combo out, not running green, or are more reliant on synergy than size, Tarmogoyf is not particularly good. If everyone had a Tarmogoyf, I would imagine we would see less Tarmogoyf-based decks, as people would get over the myth that Tarmogoyf is the best card ever and stop trying to cram him into absolutely everything.
Also, what? Who thinks MM2 sucks at all? The set's pretty fantastic from what I've seen.