First up, the post begins with the usua Combined Arms Detachment, which you can tailor accordingly to create a Thousand Sons flavored Combined Arms Detachment. As you probably know by now (if you're familiar with Chaos Space Marines armies), in the vanila Chaos Space Marines codex you can take Thousand Sons (or Rubric Marines) as your Elites choice, but that's about it. So you can still take the new Thousand Sons units as featured in the Traitor Legions codex supplement or use the new datasheets for your new Thousand Sons models in your current Chaos Space Marines army if you sod desire.
However, why would you want to do that?
Raiders of Lost Knowledge
Oh, by the way, you can take Rubric Marines as your Troops choice, so if you're not fond of Tzaangors, you can just take Rubric Marines as Troops to fulfill your normal Combined Arms Detachment requirements. Hip hip hooray. Speaking of which, if Ahriman is your Warlord, he seems to grant your army Infiltrate, or at least infantry units anyway. The Warhammer Community post jokes about Infiltrating 20 Rubric Marines into your opponent's Deployment Zone on turn 1, but I'm pretty sure there's the 12" out of sight rule and 18" within sight rule that you've to take into account, so no abuse of Infiltration there.
Lords of the Silver Towers
Apparently, if you want to play horde style with your Thousand Sons because you kind of hate how elite and how few in numbers they are, and like me you're used to fielding hordes of cheap bodies (Imperial Guard, baby!)...well, actually I'm different because I field armor companies filled with tanks, so never mind. In any case, you do have the option to field masses of Tzaangors because each of these guys are only 7 points each - 8 if you give them an autopistol. Why would you want to do that? Because Rubric Marines are extremely expensive at 23 points per model - more than 3 times the cost of a Tzaangor.
So if you prefer to build a small elite force of nothing but psykers and screw the Rubric Marines, you can actually just build an army with a lot of Sorcerers/Exalted Sorcerers and a lot more Tzaangors. Yay. The Warhammer Community recommends that you make use of the smaller formations in the book, such as the War Coven and Tzaangor Warherd, because Exalted Sorcerers and Tzaangors are at their best at this. This allows you to spam ridiculous psychic powers and still have the numbers of bodies to capture objectives. Hoo-rah!
Legion at War
Warhammer Community, as usual, recommends that you bring along Magnus in these really big games because he's a beast, quite frankly. I think you remember my post on his stats and stuff the other day, just look to that to have an idea how broken he is (he still gets squashed by a Strength D weapon though, if you roll a 6). The Warhammer Community likes the Sekhmet Conclave the most because you get to field Magnus in it PLUS a horde of Scarab Occult Terminators, and potentially boost Magnus's toughness to 8. Or you can replace Magnus with any of his chief Lieutenants such as Ahriman or an Exalted Sorcerer, up to you. In any case, this formation makes him a beast, and you can tailor your Sons of Magnus Detachment accordingly.
That's all the post had, and don't worry. Once I get my hands on the actual book next week (I think), I'll cover all the formations and do an in-depth analysis. I think I'll also cover the Tzeentch Daemons formations as well to complete the thing, I always had a soft spot for Tzeentch after all.
Emperor willing, the book should arrive sometime next week (it's officially released on 3rd December, this Saturday), so look forward for more updates then! FOR THE EMPEROR! Don't worry, the Thousand Sons are still loyal to the Emperor...who am I kidding...