|And they still didn't hit anything|
Two of the big changes in 6th ed 40K are how flyers and psychic powers work, and both have become more prevalent as a result. Partly due to their being harder to stop.
For flyers there are some counters, but they're generally limited outside of just bringing more of your own, which only makes flyers more prevalent. You can take pot shots with your non-Skyfire units, but your chance of success is low.
In 5th edition, the Space Marine Librarian was frequently seen, not for what he himself could do, but mostly for his psychic hood, providing a pretty big area of decent anti-psyker protection. No more - Deny the Witch, while ubiquitous, is much more limited in effectiveness overall. A number of the powers, those that target the psyker themselves or a friendly unit, can't be stopped by Deny the Witch at all.
At the moment, the game seems to be set up so that flyers will get through, and that psykers will generally be able to actually use their powers. I don't think that's an accident, and I think that it will continue throughout the edition. 40K is set up so that people get to use their toys.
People have been waiting anxiously for new books to include lots of cheap, effective Skyfire, but it's not here yet (CSM), and in my opinion, it's not coming. We will see some Skyfire and possibly even Interceptor in most books, but it will not be so good that we will see flyers disappear from the tables. Codex: Chaos Space Marines was the first chance to see where it was going, and it did not go the way of making flyers impotent. Flakk missiles are limited, expensive, and not terribly effective against the better-armored flyers. Even CSM's own flyer isn't that great of an anti-air platform, being much more suited to a ground attack role.
Expect more of the same for Dark Angels and other future books - some options to give you a little more than that sole quad-gun or icarus lascannon, but not a ton. And there especially won't be a lot of Interceptor.
Similarly with psychic powers. Just as GW wants people to get some use out of their flyers, they want people to get some use out of their psykers. Expect to see very little (my guess is zero) in real solid wide-ranging anti-psyker defenses in upcoming books. The few that remain, like Runes of Warding and Runic Weapons will get phased out. I'm surprised that they didn't FAQ them away right at the start of the edition, like they changed psychic hoods. They made all these powers; they want them to be used.
In other ways, defense is still strong - various saves, toughness boosts counting for instant death, feel no pain being harder to bypass, some of the changes to vehicles. It's part of the same trend in my eyes - making it more likely that you can get at least some use out of your cool stuff. You may still die, but at least you had a chance.
So expect flyers and psykers to stick around for quite a while. Get used to them.
But hey, you could always roll a six.