The Collaborative International Dictionary of English v.0.48:

Talker \Talk"er\, n.
   1. One who talks; especially, one who is noted for his power
      of conversing readily or agreeably; a conversationist.
      [1913 Webster]

            There probably were never four talkers more
            admirable in four different ways than Johnson,
            Burke, Beauclerk, and Garrick.        --Macaulay.
      [1913 Webster]

   2. A loquacious person, male or female; a prattler; a
      babbler; also, a boaster; a braggart; -- used in contempt
      or reproach. --Jer. Taylor.
      [1913 Webster]

WordNet (r) 3.0 (2006):

talker
    n 1: someone who expresses in language; someone who talks
         (especially someone who delivers a public speech or someone
         especially garrulous); "the speaker at commencement"; "an
         utterer of useful maxims" [syn: speaker, talker,
         utterer, verbalizer, verbaliser]

Moby Thesaurus II by Grady Ward, 1.0:

46 Moby Thesaurus words for "talker":
   blatherskite, blowhard, blusterer, chatterbox, collocutor,
   colloquialist, conversational partner, conversationalist,
   converser, debater, declaimer, demagogue, dialogist, discourser,
   gasbag, haranguer, interlocutor, interlocutress, interlocutrice,
   interlocutrix, jawsmith, keynoter, lecturer, orator, palaverer,
   panelist, parleyer, patterer, public speaker, rabble-rouser,
   ranter, sayer, show-off, speaker, speecher, speechifier,
   speechmaker, spellbinder, spieler, spokesman, spokeswoman, spouter,
   swaggerer, tub-thumper, utterer, windbag