Burst of Speed
Sorcery
Creatures you control gain haste until end of turn. (They can attack and 
even if they just came under your control.)
Great generals inspire by example. Goblin chieftains inspire by electrifying the barracks.
Zoltan Boros & Gabor Szikszai
Magic 2010 (M10)
• #129Rulings
Burst of Speed affects only creatures you control at the time it resolves. It won’t affect creatures that come under your control later in the turn.
(wotc • 2009-10-01)
Rulings
Burst of Speed affects only creatures you control at the time it resolves. It won’t affect creatures that come under your control later in the turn.
(wotc • 2009-10-01)