FLG stream gave a lot of info. The bad, as far as I could see: Eldar got hit hard apparently - their opinion from playtesting was that they were simply slightly too expensive overall. If it comes up - playing against 3+ Knights at 2000 points still doesn't make for a very exciting game (who would have guessed?) Not invincible, but simply not very interesting. Flyers (in the 7th edition sense) are pretty meh now, apparently. Not terrible, but not great either, with a couple of exceptions. Examples of the latter were Dakkajets, Heldrakes and DE fighters. A couple of other units were called out for not being awesome, but none really came up as "insane crap, never use".
The good: pretty much everything else. One thing they stressed: LOS blocking terrain is pretty essential for a good game. First turn charges are very possible for many units and armies, so screening units are worth their weight in gold. Both CC and shooting are super deadly, and multiple layer defenses (like rerollable 3++ save plus fnp and whatnot) that made last editions deathstars possible are almost completely gone. Offense is stronger overall. Many armies get their secret sauce from character aura buffs, and layering those (6" reroll to hit, in cc and shooting, bubbles are quite common for example). Again, most of those tend to be offensive in nature though. Games will be much quicker - they cited an average of about 1,5 hours for a 2000 points game for them (although they did say that as avid tournament players, they'd probably play faster than your average joe).
When asked for combos and tricks they used, a couple came up. Even a one model unit can declare charges against multiple units that do not even need to be close to each other. The downside: each of them gets to overwatch your ass. The upside: if you have one unit 4" behind you and another 9" in front of you, declare charges against both and roll 6" for your charge distance, you'll still make combat with something. Evern if you might have preferred the other target. As for charge distance and random charges, command points came up. "Hey, if you roll a 6 and a one for your charge and it's important, simply spend a CP and reroll that one".
Consolidate moves are now "may" and not "must". Pile-in can be used to draw other nearby units into combat. The only provision of pile-in is that you need to end up closer to the nearest enemy model of the unit you're fighting - if you can do that while also getting into 1" of an unengaged unit - boom, welcome to the melee boys. Positioning in those instances is apparently crucial.
As for combos, a unit of 10 Chaos Terminators with combiflamers came up. Combine with a sorcerer with warptime power (target unit immediately moves like it's the movement phase) who has bike, deepstrike or some other means of getting upfield quickly. DS Terminators more than 9" away from enemy, move up sorcerer, warptime. Walk Terminators up close, nuke target (likely a screeing unit) with a pile of flamer hits to clear the way and then charge something valuable. No more you must charge what you shot, no more can't charge after shooting rapid/heavy. Assault weapons have a new distinction: they can be fired after advancing (=running) at -1 BS.
Standout armies: they couldn't really agree on a top 5, but Orks were mentioned as being up there, the Guard, DE, Harlequins (!), Necrons, Nids... many others were named as contenders (AdMech and SoB got a lot of warm mentions). When asked for bottom five, they didn't have much. Eldar were named, and then things like Inquisition and Custodes when used on their own. Eldar are apparently mitigated a ton when used in an Ynnari list, combined with DE and Harlequins. They stressed Eldar units were still good, they still have a couple of great standouts, but overall they're just too points intensive. And they also reminded people that the indices are very much temporary, until proper faction codexes are released. Primary reason why things like chapter tactics and legion specific stuff is currently absent (personal speculation: I think the codices will also bring back some relics and stuff).
Overall, I had a really good impression. Still very much looking forward to the release!
