The Collaborative International Dictionary of English v.0.48:

Noncommittal \Non`com*mit"tal\, n.
   A state of not being committed or pledged; forbearance or
   refusal to commit one's self. Also used adjectively.
   [1913 Webster]

WordNet (r) 3.0 (2006):

noncommittal
    adj 1: refusing to bind oneself to a particular course of action
           or view or the like; "her boyfriend was noncommittal
           about their future together"

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "noncommittal":
   canny, careful, cautious, circumspect, constrained, cool,
   deliberate, discreet, gingerly, guarded, heedful, hesitant,
   incommunicable, judicious, leaving out nothing, mindful, on guard,
   overlooking no possibility, pawky, politic, precautional,
   precautionary, precautious, prudent, regardful, reserved,
   restrained, safe, slow to act, tentative, thorough, unadventurous,
   uncommunicative, undaring, unenterprising, unprecipitate, wary,
   watchful