The Ravenwing fulfills most of the Dark Angels' Fast Attack choices.  While limited in Fast attack Choices, the Dark Angels have some units that can be used to good effect with the rest of the army.


Assault Marine Squad:
Like other armies, the Dark Angels codex includes assault marines.  Unfortunately, the Assault marines lack a lot of the options that other marine armies can get. Despite their shortcomings, the Dark Angels assault marines can still fulfill many of the same roles as other Assault marines from other armies.  However, with the allies rules in 6th edition, it might be more beneficial now to take assault marines as allies, especially in double FOC army lists.  

Ravenwing Attack Squadron:
Ravenwing Attack squadrons are incredibly versatile, but expensive.  6th edition gave them a little boost with true T5 and fearless, however, the nerf to outflank and the prevalence of infantry lists in 6th will make Ravenwing tough to play.  That being said, they are still a decent choice and can make a decent scoring unit, especially in the late game.  Personally, I think I would rather take Ravenwing than assault marines to fulfill this role.  The other nice thing here is that you can take an Attack bike without needing to use up an FOC slot.  I'm undecided on whether I want my allies to do what the Ravenwing does, as many armies can provide this role for much cheaper, but as it stands now, Ravenwing Attack Squadrons will still see some play time.

Ravenwing Support Squad: 
I personally think this is the worst choice in the Fast Attack section.  Land speeders are even less survivable now than before (I didn't think that would even be possible), and since one of the scenarios now awards points for killing them, you are basically giving your opponent free points if you use them.  Not to mention, other armies can now provide the same disruption/suicide role for much cheaper and they do it better.  This will definitely become one unit that I will be replacing with allies (which sucks as I have 15 Ravenwing Land Speeders).