Odyssey in Extended
Whenever a new set comes out, everyone always looks to see what new cards are going to affect Constructed. With Odyssey, a number of pundits complained that there just weren't many good cards. The situation was exacerbated by the fact that all the pros were busy playtesting for an Extended format Pro Tour and so they were looking at Odyssey with much higher standards in mind. Many complained that Shadowmage Infiltrator was the only good card and only two others - Firebolt and Barbarian Ring - would even see play.
I guess that's why they play out the games.
It turns out that Odyssey cards are breaking out all over. Brian Davis and Craig Wescoe and running "Song of Flood," which includes a whopping 18 Odyssey cards. They use Song of Blood to fill up the graveyard and get them to Threshold. That makes Nimble Mongoose and Werebear go large, plus it activates Barbarian Ring. They also run Wild Mongrel and Druid Lyrist. Interestingly, R#D actually considered reprinting both Song of Blood and Mulch in Odyssey, but testing showed that they were too good with threshold, especially in limited, and that no common should put that many cards into the graveyard at once. At the time I'm writing this Davis is 3-0.
Team CMU developed a deck around Zombie Infestation. They filled their deck with graveyard recursion like Krovikan Horror, Ashen Ghoul, Squee, and Death Spark but it's the Odyssey cards - Zombie Infestation and Buried Alive - that really make the deck run. Ok, fine, Buried Alive was legal in Extended before Odyssey came out, but I swear I saw some of them playing Odyssey versions of the card. After two rounds the four members of Team CMU were 7-1 with their deck.
Your Move Games is also running a Zombie Infestation deck, though theirs is a more traditional Reanimator deck. The Infestation, along with Entomb, puts fatties like Verdant Force or Multani, Maro-Sorcerer into the graveyard so reanimation spells like Reanimate and Exhume can put them into play. Jens Thoren's version of Reanimator also uses Careful Study to allow himself to discard his fatties.
Adrian Sullivan and company designed a Holistic Wisdom deck designed to cast accumulated knowledge over and over again and recurse removal spells until the opponent is dead. John Shuler is running the design. I also heard from multiple players that their #2 deck was a 250ish-card Battle of Wits deck! Alas, I'm unaware of anyone who actually ran the big deck in this tournament.
Odyssey's impact is also being felt in sideboards. Jon Finkel and Chris Pikula have Engulfing Flames in their 'board where it can potentially kill two Spectral Lynxes or River Boas. I have seen other sideboards with Divert, Aegis of Honor, Coffin Purge, and even Skeletal Scrying.
I've seen Oath decks with one Standstill to tutor for. I've seen Tainted Pact used as a tutor in decks that even went so far as to run snow-covered lands so they would have fewer copies of each basic to screw up the Pact. I've even seen a few copies of Call of the Herd putting elephant tokens into play. Then there are the random cards like Pilgrim of Justice that probably don't deserve to actually get played, but are getting played anyway.
Finkel is definitely the most played Odyssey card and the next two are indeed Barbarian Ring followed by Firebolt, but all in all there definitely appears to be a lot more depth and a lot more subtlety to Odyssey than many Internet writers have given it credit for.