Here are references to some recent papers covering important topics in aphasia:
Otsuki M, Soma Y, Yoshimura N, Miyashita K, Nagatsuka K, Naritomi H. How to improve repetition ability in patients with Wernicke's aphasia: The effect of a disguised task. Journal of Neurology, Neurosurgery, and Psychiatry. 2005 May; 76(5): 733-735.
Grossman M, Moore P. A longitudinal study of sentence comprehension difficulty in primary progressive aphasia. Journal of Neurology, Neurosurgery, and Psychiatry. 2005 May; 76(5): 644-649.
Crosson B, Moore AB, Gopinath K, White KD, Wierenga CE, Gaiefsky ME, Fabrizio KS, Peck KK, Soltysik D, Milsted C, Briggs RW, Conway TW, Gonzalez Rothi LJ. Role of the right and left hemispheres in recovery of function during treatment of intention in aphasia. Journal of Cognitive Neuroscience 2005 Mar; 17(3): 392-406.
Bakheit A. Drug treatment of poststroke aphasia. Expert Rev Neurother. 2004 Mar; 4(2): 211-217.
Grossman M, Ash S. Primary progressive aphasia: A review. Neurocase. 2004 Feb; 10(1): 3-18.