The most played deck—barely—at this tournament is blue/green. Whether madness, threshold, Quiet Speculation or some amalgamation there of, this deck is out in force. A total of 17 players out of 110 played blue/green, not an astonishing statistic, just a healthy showing for the deck that dominated the last PTQ season.
Right on the tail of the Wild Mongrel-driven blue/green are two engine-based decks. Both Mirari's Wake Combo and Astral Slide/Lightning Rift cycling decks fill up almost a quarter of the field. The Wake deck was a huge up-and-comer towards the end of the Block season, and was also a big hit at the Magic Invitational, being the deck of choice for Invitational winner Jens Thoren. The Slide/Rift decks, utilizing the reintroduction of cycling into Magic, abuses the cheep cost of the cycling cards and the triggered abilities of Astral Slide and Lightning Rift to continually "phase out" or "shock" anything they see. Many of these decks are running Teroh's Faithful as a redundant blocker that can easily be slided out for a quick four life gain. There has also been tremendous innovation on these decks, and many have strayed from traditional white/red, dipping into green for Krosan Tusker, Naturalize, and even Cartographer, which can go infinite with a cycling land and an Astral Slide.
When you leave behind the dominant decks, there is a veritable hodgepodge of magical happenings out there. You have some Sligh out there, also focused with Onslaught cards into a beating machine. Headed by Goblin Piledriver and Sparksmiths, today's Sligh decks seem like super agro board control, instead of a beatdown deck that goes for the throat. The truth is, the creatures these days are just not that well suited for beating down, with no 2 powered one drops and precious few 2 powered creatures, except of course for the very powerful Goblin Piledriver.
There were at least five decks sporting Opposition, some playing variants of the deck Gabriel Nassif used at the Invitational, posting a 3-0 record in the Standard portion. Others are straight up blue/green, with Squirrels Nest and everything. Psychatog and Zombie Infestation were present in a few decks, Infestation taking up some space in some weird madness concoction.
Former Invitational competitor Scott Richards found himself in Houston but without an invite. He is playing a very eccentric four-color madness deck with everything from Zombie Infestation, Wild Mongrel, Arrogant Wurm, Anger, Basking Rootwalla, and Ray of Revelation.
The top decks, in order of players running them, is as follows.
Blue Green 17
Green White 12
A last note... I found two Wizard decks in the tournament, one of them sitting across from an opponent who seemed very, very happy as he slipped a couple copies of Empress Llawan into his deck from his sideboard.