The Collaborative International Dictionary of English v.0.48:

Hastiness \Has"ti*ness\, n.
   The quality or state of being hasty; haste; precipitation;
   rashness; quickness of temper.
   [1913 Webster]

WordNet (r) 3.0 (2006):

hastiness
    n 1: overly eager speed (and possible carelessness); "he soon
         regretted his haste" [syn: haste, hastiness, hurry,
         hurriedness, precipitation]
    2: hasty impulsiveness

Moby Thesaurus II by Grady Ward, 1.0:

76 Moby Thesaurus words for "hastiness":
   abandon, abruptness, alacrity, careless abandon, carelessness,
   casualness, cursoriness, desperateness, devil-may-careness,
   disregardfulness, easiness, expeditiousness, fecklessness,
   feverishness, forgetfulness, forwardness, furiousness, haste,
   heedlessness, hotheadedness, hurriedness, impatience, impetuosity,
   impetuousness, improvidence, impulse, impulsiveness,
   inconsiderateness, inconsideration, indifference, insouciance,
   lack of foresight, lax stewardship, laziness, negligence, oblivion,
   offhandedness, overeagerness, overenthusiasm, overhastiness,
   overzealousness, perfunctoriness, poor husbandry, precipitance,
   precipitancy, precipitateness, precipitation, precipitousness,
   precociousness, precocity, prematureness, prematurity, promptness,
   quickness, rashness, recklessness, regardlessness, rush,
   shiftlessness, speed, sprezzatura, suddenness, swiftness,
   tactlessness, thoughtlessness, thriftlessness, unheedfulness,
   unmindfulness, unpreparedness, unreadiness, unsolicitousness,
   unsolicitude, unthinkingness, untimeliness, wantonness, wildness