There's still a lot of Magic left to be played as I write this between rounds 8 and 9, but it looks like the Pro Tour is boiling down to just two main deck types: Mono-Black and Blue-Green. There's several other decks that could still surprise, including Blue-Black Psychatog and the Magic Colony's Blue-Red-splash-black Compulsion deck, but the two major forces warring for dominance of the Odyssey-block Constructed metagame are set.
Team Godzilla claims Upheaval is the way to go, but in the same breath they lament the loss of their best sideboard constructer – Scott Johns – for this Pro Tour. He skipped this Tour because his wife is having a baby. Unfortunately for Team Godzilla, I think this Pro Tour will be won or lost based on the sideboarding quality. They think Upheaval is enough to put them over the top against Black, but they don't have good plan for the mirror match.
When you're playing one of the two decks defining a field, you've got to have a good plan against the other one and you've got to have a good plan for the mirror match. Jens Thoren is 8-0 as I write this, but he's also disappointed in his mirror match sideboard technology. Many of the mono-black decks are running Braids for the mirror, but he didn't think of that – he just plain missed it. He does have a full complement of Rancid Earths and Mind Sludges, though. He thinks those are crucial to the mirror, and they've been enough so far.
When the dust settles at the end of day 2, the players left standing are going to be those who have good sideboards. No one I've talked to sounds particularly confident at this point so it'll be interesting to see who's right and who's wrong. Meanwhile $200,000 hangs in balance, up for grabs to whoever did their playtesting homework correctly.