Primal Ponies can fly? o.O thats news to me..but seeing as how Sleipnir is considered a primal mount (seeing as how it plays Odin's Theme) I'm going to assume it will be able to fly..maybe not right of the bat in 3.0 since Yoshi and friends have mentioned that older mounts like the Ahriman will be able to fly in a later patch (something like 3.1 or 3.2) and not as soon as Heavensward launches.

18 days for early access!...i'm dieing over here waiting x.x