Yeah, it's really hard to say with the Blood Angels. Their Primarch had wings and was known to be one of the best melee Primarchs. They were also known as a fast Legion- first to the fight kinda thing. We can see that in
40K with all the tanks being fast, the deep striking, and jump pack options for just about everything.
In 30K? Well, all the Legions so far have some kind of derivative squad of a current Legion squad. I.e., for the Sons of Horus, they have Justarian Terminators that are either a Command Squad or special unit of Terminators, and the Reaver Squad, which came from the Legion Destroyer squads. In addition, there is a Legion specific Rite of War for the Sons of Horus that changes the Force Organization chart around.
The Blood Angels could just go either way- units with Jump Packs or maybe fast vehicles. They won't have the Red Thirst, so the Death Company, focus on Sanguinary Priests, and Librarian Dreads will not be around. That kinda leaves a Sanguinary Guard style unit, and that's probably what we'll see. A unit with Jump packs, artificer armor, and power weapons. They'll probably get a rule similar to the Descent of Angels, where everything can be held in reserve and then deep strike- maybe the return of the deep striking Land Raider? Or, OMG, deep striking Fellblade?

Pretty sure their force organization chart will center around fast attack troops (not Speeders or bikes/jet bikes) and elites with jump packs. Heavy Support might be like in the Sons of Horus- you need more Fast Attack choices then Heavy Support, and they will have to take a fast Rhino/Razorback. If any Legion were to get a fast Land Raider, I'd imagine it would be the Blood Angels.
Book Six was supposedly due 2015, and here we are on December 31st, 2015 with no book. Maybe Q1 2016? I hope so! The book I'm really looking forward to: Book 7, Retaliation Prospero and the Space Wolves!