The Collaborative International Dictionary of English v.0.48:

Unanticipated \Unanticipated\
   See anticipated.

WordNet (r) 3.0 (2006):

unanticipated
    adj 1: not anticipated; "unanticipated and disconcerting lines
           of development"- H.W.Glidden; "unforeseen circumstances";
           "a virtue unlooked-for in people so full of energy";
           "like a bolt out of the blue" [syn: unanticipated,
           unforeseen, unlooked-for, out of the blue(p)]

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "unanticipated":
   abrupt, electrifying, extraordinary, hasty, headlong, impetuous,
   improbable, impulsive, more than expected, nerve-shattering,
   out-of-the-way, past expectation, precipitant, precipitate,
   precipitous, quick, shocking, speedy, startling, sudden,
   surprising, swift, unannounced, undivined, unexpected,
   unforeseeable, unforeseen, unguessed, unheralded, unhoped for,
   unlooked-for, unpredictable, unpredicted, unprepared for,
   without warning